1 - Evolutionary Explanations For Partner Preferences

Question 1

Define evolution

Answer 1

Process by which living species develop over time to adapt to their environment

Question 2

What are the two needs that drive human behaviour + partner selection

Answer 2

• Need to survive

- Need to reproduce

Question 3

Define natural selection

Answer 3

Selecting characteristics that aid chances of survival

Question 4

Define sexual selection

Answer 4

Selecting characteristics that aid chances of successful reproduction

Question 5

Give an example of the need to survive + the need to reproduce coming into conflict

Answer 5

Peacock tails

• Chance of survival: lowered, bright stands out to predators
• Chance of successful reproduction: raised, impressive to mates

Question 6

Define anisogamy

Answer 6

The difference between male + female gametes, which come together to reproduce

Question 7

What does anisogamy (difference in male + female gametes) cause?

Answer 7

Difference in male + female reproductive behaviour

Question 8

Outline the properties of male gametes

Answer 8

Gamete: sperm

• Plentiful (millions per ejaculation)
• Produced from puberty to death
• Require less energy to produce

Question 9

Outline the properties of female gametes

Answer 9

Gamete: egg (ovum)

• Less plentiful (one per month)
• Produced from puberty to menopause (limited number of fertile yrs)
• Require more energy to produce

Question 10

Outline the reproductive behaviour of males

Answer 10

• Try to ‘sow seed’ to as many partners as possible
• Quantity > quality
• Use intrasexual selection

Question 11

Outline the reproductive behaviour of females

Answer 11

• Try to pick one ideal partner for raising offspring with
• Quality > quantity
• Use intersexual selection

Question 12

Define intrasexual selection

Answer 12

Sexual strategies that exist WITHIN each sex, involving competition to present oneself as the most attractive potential mate

Question 13

Who is involved in intrasexual selection?

Answer 13

• Men compete with each other (they are active)

- Women are passive

Question 14

Outline the process of intrasexual selection

Answer 14

• Males compete to make themselves appear most attractive to women, so they are selected as a mate
• Chosen male passes on his ‘attractive’ characteristics, making them more prevalent in the gene pool

Question 15

Define dimorphism

Answer 15

‘Two forms’

The fact that men + women look very different

Question 16

What has caused dimorphism?

Answer 16

Intrasexual selection (men have become bigger, stronger + more aggressive from competing to be chosen)

Question 17

Define intersexual selection

Answer 17

Sexual strategies that exist BETWEEN each sex, involving choosing the ‘best’ mate

Question 18

Who is involved in intersexual selection

Answer 18

• Women choose their mate (active)

Question 19

Why are women the ones who choose the mate?

Answer 19

Females invest moire time + effort in the reproductive process and ova are rarer, so women are pickier about their partner (don’t want to waste everything with a bad partner who gives bad offspring)

Question 20

Outline the process of intersexual selection

Answer 20

• Women choose men who are genetically fit + can provide them with maximum resources
• Traits perceived as ‘attractive’ by women will become more prevalent in the gene pool as they are frequently selected
• Offspring will inherit these positive characteristics which will give them an advantage (Sexy Sons Hypothesis)

Question 21

What does it mean for a mate to be genetically fit?

Answer 21

Able to protect their partner + offspring

- E.g. tall + muscular

Question 22

What does it mean for a mate to provide maximum resources?

Answer 22

Provides a range of helpful financial + physical resources

- E.g. well paid occupation + high class

Question 23

What characteristics to women predominantly look for to make up an ideal partner?

Answer 23

• Genetically fit

- Maximum resources

Question 24

Give 2 positive evaluation points for evolutionary explanations for partner preferences

Answer 24

Research to support intrasexual selection (Buss)

• Questionnaire to over 10,000 adults in 33 countries
• Asked what makes + females value in a partner
• M: Good looks, fertile (looking to compete to sow as many seeds as possible)
• F: Resources (not competitive, looking to find an actual good partner)

Research to support intersexual selection (Clark + Hatfield)
- Psych students sent across a uni to approach other students + ask for…
Date: Males 50% yes, Females 50% yes
Apartment visit: Males 69% yes, Females 6% yes
Go to bed with them: Males 75% yes, Females 0% yes
- Females rejected the more intimate offer (more choosy than men)

Question 25

What are the two methods involved in partner selection?

Answer 25

• Intrasexual selection

- Intersexual selection

Question 26

Give 2 negative evaluation points for evolutionary explanations for partner preferences

Answer 26

Social + cultural norms may be reducing intersexual selection by women

• Norms are shifting + reducing some intersexual selection, suggesting partner preference isn’t purely evolutionary (biological)
• Women more valued in workplace (less need for men with resources)
• Women have more access to contraception (don’t view partner as set with them for life or to give precious offspring)
• Partner preferences are also influenced by social + cultural norms, which are shifting over time

Doesn’t explain homosexual relationships

• The evolutionary explanation can’t explain homosexuality
• Gay + lesbian couples don’t seek partners based on reproductive aim
• Explanation can’t explain why homosexual couples pick their partners