BIOLOGICAL RHYTMS - INFRADIAN

Question 1

Biological rhythms

Answer 1

• internal body processes that occur as a series of repeated events in a cycle.

Question 2

Infradian rhythms (IR)

Answer 2

• biological rhythms that occur less than once every 24 hours, but more than once a year.

Question 3

an exp of bio rhytms

Answer 3

• Menstrual cycle occurs every 28 days.
• It controls a female’s ovulation and fertility by varying the levels of progesterone and oestrogen across a 28 day cycle

Question 4

Stern and
McClintock

Answer 4

• found that 68% of women experienced changes in their menstrual cycle which brought them
  closer to the cycle of their ‘odour donor’.
• Also found that meeting a new man can shorten a female’s menstrual cycle.
• This has evolutionary advantages as they can mate immediately

Question 5

One strength of research into IR is that menstrual cycles have adaptive values.

Answer 5

• For example, menstrual synchronisation means that all women can give birth at the same time and can share in the childcare.
• This leads to increased chances of survival for the offspring as mothers would be able to aid each other
  with breastfeeding.
• However, the findings are inconclusive as we cannot demonstrate that synchronisation is beneficial.
• Also with increased synchronisation there is higher competition between mates which leads to conflict as females would fight for the high status males

Question 6

One limitation of research into IR is that it has methodological issues.

Answer 6

• There are too many variables to consider that may affect changes in a woman’s menstrual cycle.
• For instance, factors such as diet, stress and exercisemay act as confounding variables.
• This weakens the cause and effect relationship between pheromones and menstrual synchronisation meaning we are unable to pinpoint exactly what causes two females to sync.
• Naturally, if both cycles go on for a long period they’ll eventually sync.
• Yet, as humans we have cognitive biases meaning we believe the things that make the most sense to us despite a lack of evidence

Question 7

One limitation of research into IR is that it’s not generalisable.

Answer 7

• For example, he used a small scale sample of women, which means it’s not accurately representative of the whole population.
• This is a disadvantage as it lacks population validity and so cannot be used to explain the behaviour of other cultures.
• Furthermore, it relies on self report methods which are open to social desirability which may lead
  to findings being inaccurate.
• Therefore, this casts doubt on the research which decreases its credibility.

Question 8

One strength of research into IR is that there is supporting research.

Answer 8

• For example, Russel et al. collected samples of sweat from a group of women and applied it to the upper lip of a second group of women.
• Even though the women were kept separate, it was found that their menstrual cycles became synchronised .
• This clearly shows that synchronisation is influenced by pheromones, as shown by women whose cycles changed in response.
• This is an advantage as it clearly demonstrates the principles of the theory and so increases the validity of the theory.