Sex Differences In Parental Investment

Question 1

What do we mean by parental investment?

Answer 1

‘Any investment by the parent in an individual that increases the offspring’s chance of surviving (and hence reproductive success) at the cost of the parent’s ability to invest in other offspring’

Question 2

Name 3 examples of parental investment

Answer 2

1) Resources
2) Time spent teaching the offspring
3) Risks taken to protect the offspring

Question 3

Outline maternal investment (3 main points)

Answer 3

1) The female egg is very costly to produce as have to nourish offspring for 9 months so limited to the number of offspring and breastfeeding inhibits fertility
2) Essentially they make the greater prenatal and postnatal contribution
3) Also, can always be certain that she is the mother due to internal fertilisation, whereas a man cannot

Question 4

How long can breastfeeding last for?

Answer 4

In the UK, 3-12 months but it can be up to 4 years in other countries

Question 5

Why can a mother be certain she is the mother but a man cannot be certain he is the father?

Answer 5

Internal fertilisation

Question 6

Outline paternal investment

Answer 6

Males either mate with as many females as possible or only guard one female to maximise reproductive success - can potentially father an unlimited number of offspring

Question 7

What did Trivers argue about paternal investment?

Answer 7

There is an optimum number of offspring for each parent - a low-investing male could afford many offspring and favour a quantity rather than quality approach and females prefer quality and so are more choosy

Question 8

What is the highest number of offspring conceived by a female?

Answer 8

69

Question 9

What is the highest number of offspring conceived by a male?

Answer 9

867

Question 10

What do both men and women look for in the short-term?

Answer 10

Men look for fertility and women look for ‘mate insurance’

Question 11

What do both men and women look for in the long-term?

Answer 11

Men look for parenting skills and faithfulness and women look for resources, commitment and protection

Question 12

Name 2 positive evaluative points for sex differences in paternal investment

Answer 12

1) Daly & Wilson (80)

2) Geher (07)

Question 13

Outline Daly & Wilson (80)

Answer 13

Children under the age of 2 are at least 60 times more likely to be killed by a step-parent (almost always a stepfather) than by a natural parent which is what evolutionary theory would predict as genetically unrelated

Question 14

What does Geher (07) show?

Answer 14

Evidence suggesting males tend to be less prepared than females

Question 15

Outline Geher (07)

Answer 15

Studied 91 undergraduates who completed a paternal investment perception scale and were exposed to various parenting related scenarios - found no sex differences in self-report responses to parenting on the scale but there were clear differences in the ANS arousal to different parenting scenarios as males showed significantly increased heart rates when presented with scenarios that emphasised the costs of parenting - so, males biologically less prepared than females to confront issues associated with parenting

Question 16

Name 4 negative evaluative points about sex differences in paternal investment

Answer 16

1) Most stepfathers do not kill/abuse their stepchildren & minority of biological fathers do
2) Anderson (99)
3) Sex differences in jealousy - Buss (92)
4) Difficult for the theory to explain neonaticide

Question 17

What is neonaticide?

Answer 17

The killing of a new-born baby

Question 18

Outline Anderson (99)

Answer 18

Measured the resources invested by father and stepfather and found that men appeared to not discriminate between children born to their current partner from a previous relationship and their own children from a previous relationship

Question 19

Explain sex differences in jealousy for sex differences in paternal investment

Answer 19

Buss (92) - ppts imagined their partners either having sex or being in love with someone else and measured their stress responses and found men were more stressed when their partner was sexually unfaithful and women were more stressed when their partners were emotionally unfaithful

Question 20

Explain why it is difficult for the theory to explain neonaticide for sex differences in paternal investment

Answer 20

Doesn’t make sense for a woman to kill her new-born baby - Pinker (97) said when such an act takes place, it is usually in conditions of poverty and could be regarded as an adaptationist response

Question 21

Name 3 IDA points for sex differences in paternal investment

Answer 21

1) Culturally biased
2) Insights from non-human species
3) Reductionist

Question 22

Explain why theories for sex differences in paternal investment are culturally biased

Answer 22

They don’t look at paternal investment in collectivist cultures which may be very different so not necessarily a universal theory

Question 23

Explain insights from non-human species for sex differences in paternal investment

Answer 23

We can better understand the origins of human paternal behaviour by making a comparative analysis of parental investment in closely related species - the 2 most closely related are chimps and bonobos and in both males show little or no parental investment which suggests the emergence of male parenting in humans either represents a dramatic evolutionary change over our primate ancestors or the contribution of cultural learning

Question 24

Explain how theories about sex differences in paternal investment are reductionist

Answer 24

Rowe (02) suggests an explanation of paternal investment based on just evolutionary factors is severely limited - men’s parental behaviour depends on various personal and social conditions, including the quality of the relationship with the mother, the characteristics of the child and the personality characteristics of the father

Question 25

What does Belsky (91) suggest about sex differences in paternal investment

Answer 25

Claims childhood experiences like parental divorce tends to correlate with the degree to which men invest in the upbringing and care of their own child