Evolution and human behaviour

Question 1

What is evolutionary psychology?

Answer 1

Understanding modern behaviour from a psychological basis
The combination of cognitive psychology (which tells us the mind has a very complex design) and evolutionary biology (which tells us that complex designs can only come about by natural selection).
So, the mind must be an evolved adaptation
Takes the view that modern behaviour was shaped in an EEA, results from inherited body and mind from the past

Question 2

What is human behavioural ecology?

Answer 2

Biological approach, measurable fitness benefits
Measures how different behaviours lead to different levels of reproductive success.
Uses lifetime reproductive success as a measure of adaptiveness of current behaviour

Question 3

3 areas where there have been recent developments

Answer 3

Communication and language
Mate choice and reproductive strategies
Cooperation

Question 4

1: communication and language

Answer 4

Many theories for why language evolved. Include:
Grooming hypothesis
Language as a sexually selected trait

Question 5

1: communication and language

Grooming hypothesis

Answer 5

Dunbar, positive correlations between social group size, time spent grooming, and brain size.
Language evolved for ‘social grooming’ as group size increased.
Hard to test…

Question 6

1: communication and language

Sexually selected trait hypothesis

Answer 6

Miller - idea that the brain is like a peacocks tail. Females find males with better cognitive capacities more attractive
Runaway selection for creative intelligence?
Men have higher creative outputs than women. Married scientists have higher scientific outputs and reach their peak earlier
Could explain the over complexity of human language: English has 80,000 + words. However there is no clear dimorphism and its learned from a young age… may not be sexually selected

Question 7

2: mate choice and reproductive strategies

Answer 7

Can we see the same principles in human mate choice as we do in other animal species?

• sexual conflict and mate choice
• fitness benefits
• value of granny

Question 8

2: mate choice

Sexual conflict

Answer 8

Women have the same constraints as other female mammals. So, we would expect them to be choosier and for men to desire more sexual partners
Was indeed found in a study on an american campus: asked would you like to go out with me, come to my flat, go to bed with me tonight?
First Q was 50/50 yes, 2nd was 69% men, 6% women, 3rd was 0% women, 75% men

Question 9

2: mate choice
Sexual conflict
we would predict that women would want men with:

Answer 9

Good genes (direct)
Signalled by physical traits relating to fitness, age, masculinity. Symmetry is preferred, and skin health (good immune system). Women choose men that are slightly genetically similar to them
Good resources (indirect)
Women look for men who can provide for them and their future children. Look for older men, good education, intelligence (personal ads study). This is likely to correlate with dominance/success -> good genes

Question 10

2: mate choice
Fitness benefits
do mate preferences lead to actual mating success?

Answer 10

Ache of eastern Paraguay, males that are better hunters have more EPC and illegitimate children
Also in modern western society: Nettle found that the more money you have, the more offspring you have (M, opposite in F). Not as strong as it used to be

Question 11

2: mate choice

the value of the granny

Answer 11

Lumar investigated the value of family in increasing offspring fitness, and was interested in the longevity of life. Why do women live longer?
Humans are the only species who live so long post-menopause. Is there selection for long life to improve offspring (and grandchild) survival?
Finland and Canada - the longer granny lives, the more grandchildren survive

Question 12

3: cooperation

why are we so helpful?

Answer 12

Explanations for animal cooperation can’t be used to explain behaviour like donating blood, where there is no indirect fitness benefit.
Conspicuous generosity builds strong relationships in small groups. Students are more likely to donate if they receive a badge.. Reputation management as an explanation

Question 13

3: cooperation

how does being watched affect donations?

Answer 13

Nettle: people donated more to the honesty coffee box when pictures of eyes were present. Is cooperation a signal to enhance our reputation?

Question 14

3: cooperation

has altruism evolved as a sexual signal?

Answer 14

People preferentially cooperate with more attractive people
Cooperative behaviour can also enhance the attractiveness of the individual
So, costly altruistic behaviour can accrue benefits that aren’t direct but still are present, in terms of mate choice and sexual selection