6.7: Infradian rhythms

Question 1

Discuss research into infradian and/or ultradian rhythms (16 marks)

Answer 1

Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women

Question 2

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.

Answer 2

Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones

Question 3

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock

Answer 3

McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor

Question 4

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Answer 4

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5

Question 5

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
What is one of the most effective treatments for SAD?

Answer 5

One of the most effective treatments for SAD is phototherapy

Question 6

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
What is this?

Answer 6

This is a lightbox that simulates very strong light in the morning and evening

Question 7

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
What is it thought to do?

Answer 7

It is thought to reset melatonin levels in people with SAD

Question 8

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.

Answer 8

Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers

Question 9

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

First AO3 PEEL paragraph

Answer 9

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment)

Question 10

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
What does this do?

Answer 10

This casts doubts on the chemical influence of phototherapy

Question 11

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this,

Answer 11

Despite this, Eastman et al’s research has economic implications in the area of shift work

Question 12

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
Why is this?

Answer 12

This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning

Question 13

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
What does this show?

Answer 13

This shows that research into infradian rhythms has useful real world application

Question 14

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

Second AO3 PEEL paragraph

Answer 14

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress

Question 15

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
What does this mean?

Answer 15

This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance

Question 16

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies

Answer 16

Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research

Question 17

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.

Answer 17

The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony

Question 18

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
Why does this matter?

Answer 18

This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors

Question 19

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However,

Answer 19

However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely

Question 20

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
What does this show?

Answer 20

This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated

Question 21

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

Third AO3 PEEL paragraph

Answer 21

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation

Question 22

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to

Answer 22

Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates

Question 23

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
Example

Answer 23

For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time

Question 24

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
What would this mean?

Answer 24

This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival

Question 25

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
Who is this supported by?

Answer 25

This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties

Question 26

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
What would this fit in with?

Answer 26

This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children

Question 27

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
What does this illustrate?

Answer 27

This illustrates the evolutionary basis of the menstrual cycle

Question 28

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

Fourth AO3 PEEL paragraph

Answer 28

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear

Question 29

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus,

Answer 29

Thus, the validity of the evolutionary perspective has been questioned by some

Question 30

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus, the validity of the evolutionary perspective has been questioned by some.
Example

Answer 30

For example, Schank (2004) argues that if there were too many females cycling together within a social group, this would produce too much mate competition for the highest quality males, thereby lowering the fitness and health potential of any potential offspring

Question 31

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus, the validity of the evolutionary perspective has been questioned by some.
For example, Schank (2004) argues that if there were too many females cycling together within a social group, this would produce too much mate competition for the highest quality males, thereby lowering the fitness and health potential of any potential offspring.
Why does this matter?

Answer 31

This matters because it suggests that evolutionary reasons for synchronisation are invalid - if synchronisation does indeed actually occur, it must be for other reasons yet to be explored

Question 32

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus, the validity of the evolutionary perspective has been questioned by some.
For example, Schank (2004) argues that if there were too many females cycling together within a social group, this would produce too much mate competition for the highest quality males, thereby lowering the fitness and health potential of any potential offspring.
This matters because it suggests that evolutionary reasons for synchronisation are invalid - if synchronisation does indeed actually occur, it must be for other reasons yet to be explored.

Fifth AO3 PEEL paragraph

Answer 32

The fifth AO3 PEEL paragraph is that much of the knowledge of the effects of pheromones on behaviour is derived from animal studies

Question 33

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus, the validity of the evolutionary perspective has been questioned by some.
For example, Schank (2004) argues that if there were too many females cycling together within a social group, this would produce too much mate competition for the highest quality males, thereby lowering the fitness and health potential of any potential offspring.
This matters because it suggests that evolutionary reasons for synchronisation are invalid - if synchronisation does indeed actually occur, it must be for other reasons yet to be explored.

The fifth AO3 PEEL paragraph is that much of the knowledge of the effects of pheromones on behaviour is derived from animal studies.
It is therefore

Answer 33

It is therefore harder to generalise the findings to humans

Question 34

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus, the validity of the evolutionary perspective has been questioned by some.
For example, Schank (2004) argues that if there were too many females cycling together within a social group, this would produce too much mate competition for the highest quality males, thereby lowering the fitness and health potential of any potential offspring.
This matters because it suggests that evolutionary reasons for synchronisation are invalid - if synchronisation does indeed actually occur, it must be for other reasons yet to be explored.

The fifth AO3 PEEL paragraph is that much of the knowledge of the effects of pheromones on behaviour is derived from animal studies.
It is therefore harder to generalise the findings to humans.

Answer 34

The role of pheromones in animal sexual selection is well-documented, such as how sea urchins release pheromones into the surrounding water so other urchins in the colony will eject their sex cells simultaneously

Question 35

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus, the validity of the evolutionary perspective has been questioned by some.
For example, Schank (2004) argues that if there were too many females cycling together within a social group, this would produce too much mate competition for the highest quality males, thereby lowering the fitness and health potential of any potential offspring.
This matters because it suggests that evolutionary reasons for synchronisation are invalid - if synchronisation does indeed actually occur, it must be for other reasons yet to be explored.

The fifth AO3 PEEL paragraph is that much of the knowledge of the effects of pheromones on behaviour is derived from animal studies.
It is therefore harder to generalise the findings to humans.
The role of pheromones in animal sexual selection is well-documented, such as how sea urchins release pheromones into the surrounding water so other urchins in the colony will eject their sex cells simultaneously.
In contrast,

Answer 35

In contrast, evidence for the effects in human behaviour remains, at best, speculative and inconclusive

Question 36

Discuss research into infradian and/or ultradian rhythms (16 marks).
Research into infradian rhythms suggests that although the menstrual cycle is an endogenous system, it may be influenced by exogenous factors, such as the cycles of other women.
Kathleen Stern and Martha McClintock (1998) demonstrated how menstrual cycles may synchronise as a result of the influence of female pheromones.
McClintock involved 29 women with a history of irregular periods.
Samples of pheromones were gathered from 9 of the women at different stages of their menstrual cycles via a cotton pad placed in their armpit.
The pads were worn for at least 8 hours to ensure that pheromones were picked up and the pads were treated with alcohol and frozen, to be rubbed on the upper lip of the other participants.
On day one, pads from the start of the menstrual cycle were applied to all 20 women, on day two they were all given a pad from the second day of the cycle, and so on.
McClintock found that 68% of the women experienced a shift in their menstrual cycle towards that of the donor.

Seasonal affective disorder (SAD) is a depressive disorder that has a seasonal pattern of onset and is described and diagnosed as a mental disorder in DSM-5.
One of the most effective treatments for SAD is phototherapy.
This is a lightbox that simulates very strong light in the morning and evening.
It is thought to reset melatonin levels in people with SAD.
Eastman et al. (1998) found that this relieves symptoms in up to 60% of sufferers.

The first AO3 PEEL paragraph is that However, Eastman et al. also recorded a placebo effect of 30% using a ‘sham negative-ion generator’ (participants were told it was another form of treatment).
This casts doubts on the chemical influence of phototherapy.
Despite this, Eastman et al’s research has economic implications in the area of shift work.
This is because companies could provide light for their employees, for example how hospitals have special lights to ensure the doctors and nurses stay awake, alert and productive late at night or in the early hours of the morning.
This shows that research into infradian rhythms has useful real world application.

The second AO3 PEEL paragraph is that as well as this, one limitation of McClintock and Stern’s study was that there were many confounding variables that could’ve affected change in a woman’s menstrual cycle, such as stress, changes in diet, exercise and stress.
This means that any supposed pattern of synchronisation is no more than would have been expected to occur by chance.
Synchronisation studies also typically involve small samples of women and rely on participants self-reporting the onset of their own cycle, meaning that the results gained may not be valid, due to social desirability bias, for example, as the women would’ve been aware they were taking part in research.
The confounding variables present also mean that the research is difficult to replicate and this is supported by Trevathan et al. (1993), who replicated McClintock’s study, but failed to find any supporting evidence of menstrual synchrony.
This matters because although menstruation is an internal mechanism, McClintock’s research suggests that the variations could be explained by external factors.
However, Travethen’s research suggests that synchronisation because of exposure to pheromones is unlikely.
This shows that the extent to which pheromones can have an effect still requires research, as supported by Wilson (1992), who challenged the idea of menstrual synchronicity, stating that experimental evidence of its existence was exaggerated.

The third AO3 PEEL paragraph is that Furthmore, research such as McClintock and Stern’s raises questions about the role of synchronisation.
Menstrual synchrony is thought by many to have evolutionary advantages and increase survival rates.
For example, for our ancestors, it may have been advantageous for females to menstruate together and therefore fall pregnant around the same time.
This would mean that they could raise children together, meaning that newborns could be cared for collectively within a social group, increasing the chances of their survival.
This is supported by Turke, who argues that that synchonrised periods have an evolutionary signifiance, because it allowed women living together to share child-caring duties.
This would fit in with the evolutionary approach that we have adapted accordingly to increase chances of survival for children.
This illustrates the evolutionary basis of the menstrual cycle.

The fourth AO3 PEEL paragraph is that However, how close women have to live together and for what period of time for menstrual synchronisation to occur is not clear.
Thus, the validity of the evolutionary perspective has been questioned by some.
For example, Schank (2004) argues that if there were too many females cycling together within a social group, this would produce too much mate competition for the highest quality males, thereby lowering the fitness and health potential of any potential offspring.
This matters because it suggests that evolutionary reasons for synchronisation are invalid - if synchronisation does indeed actually occur, it must be for other reasons yet to be explored.

The fifth AO3 PEEL paragraph is that much of the knowledge of the effects of pheromones on behaviour is derived from animal studies.
It is therefore harder to generalise the findings to humans.
The role of pheromones in animal sexual selection is well-documented, such as how sea urchins release pheromones into the surrounding water so other urchins in the colony will eject their sex cells simultaneously.
In contrast, evidence for the effects in human behaviour remains, at best, speculative and inconclusive.
What does this show?

Answer 36

This shows that due to the insufficient evidence for humans, it would be reductionist to draw conclusions about human behaviour from animal research