1 - Evolutionary Explanations For Partner Preferences Flashcards
Define evolution
Process by which living species develop over time to adapt to their environment
What are the two needs that drive human behaviour + partner selection
- Need to survive
- Need to reproduce
Define natural selection
Selecting characteristics that aid chances of survival
Define sexual selection
Selecting characteristics that aid chances of successful reproduction
Give an example of the need to survive + the need to reproduce coming into conflict
Peacock tails
- Chance of survival: lowered, bright stands out to predators
- Chance of successful reproduction: raised, impressive to mates
Define anisogamy
The difference between male + female gametes, which come together to reproduce
What does anisogamy (difference in male + female gametes) cause?
Difference in male + female reproductive behaviour
Outline the properties of male gametes
Gamete: sperm
- Plentiful (millions per ejaculation)
- Produced from puberty to death
- Require less energy to produce
Outline the properties of female gametes
Gamete: egg (ovum)
- Less plentiful (one per month)
- Produced from puberty to menopause (limited number of fertile yrs)
- Require more energy to produce
Outline the reproductive behaviour of males
- Try to ‘sow seed’ to as many partners as possible
- Quantity > quality
- Use intrasexual selection
Outline the reproductive behaviour of females
- Try to pick one ideal partner for raising offspring with
- Quality > quantity
- Use intersexual selection
Define intrasexual selection
Sexual strategies that exist WITHIN each sex, involving competition to present oneself as the most attractive potential mate
Who is involved in intrasexual selection?
- Men compete with each other (they are active)
- Women are passive
Outline the process of intrasexual selection
- 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
Define dimorphism
‘Two forms’
The fact that men + women look very different
What has caused dimorphism?
Intrasexual selection (men have become bigger, stronger + more aggressive from competing to be chosen)
Define intersexual selection
Sexual strategies that exist BETWEEN each sex, involving choosing the ‘best’ mate
Who is involved in intersexual selection
- Women choose their mate (active)
Why are women the ones who choose the mate?
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)
Outline the process of intersexual selection
- 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)
What does it mean for a mate to be genetically fit?
Able to protect their partner + offspring
- E.g. tall + muscular
What does it mean for a mate to provide maximum resources?
Provides a range of helpful financial + physical resources
- E.g. well paid occupation + high class
What characteristics to women predominantly look for to make up an ideal partner?
- Genetically fit
- Maximum resources
Give 2 positive evaluation points for evolutionary explanations for partner preferences
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)
What are the two methods involved in partner selection?
- Intrasexual selection
- Intersexual selection
Give 2 negative evaluation points for evolutionary explanations for partner preferences
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
