AQA A2 Psychology Unit 3 Relationships: Evolutionary Explanations Of Parental Investment Notes

A2 Psychology Unit 3 Relationships: Evolutionary Explanations Of Parental Investment Notes

What You Need To Know:

• Evolutionary explanations of parental investment: e.g. sex differences, parent-offspring conflict.

Evolutionary Explanations of Parental Investment:

Evolutionary explanations can be applied to parental behaviour.

Parental Investment - refers to any time, effort and energy that a parent puts towards the conception, gestation and rearing of a child that reduces their ability to invest in other offspring.

Sex differences in parental investment:

• Male investment in offspring is more variable than female, since females can be 100% certain that the child is theirs whilst men can never be sure.
• Birkhead (2002) - reports 17 women waiting for fertility treatment falling pregnant before treatment even though the husband produced no sperm.
• Apicella and Marlowe (2004) - If men think their children resemble them and feel the woman is loyal, they increase parental investment.
• Anderson (2007) - The less confident men are of paternity, the less time they spend with their offspring.

Trivers` theory of parental investment (1972):

• When the amount of energy that each sex must devote to reproduction and parental care is different, the sex with the greater burden will be the choosier.
• Human females invest much more than males, including egg production, gestation, possibly dangerous childbirth and then long term child care. Also, female fertility reduces significantly after 35 years of age, but males produce sperm from puberty to death.
• Mistakes in mate…