relationships Flashcards
evolutionary hypothesis basics
- men look for women who are likely to reproduce successfully (young and therefore fertile + physically attractive)
- women are looking for successful men who can provide for offspring (older + successful + physically strong etc)
anisogamy
form of sexual reproduction that involves union or fusion of 2 gametes that differ in size and form
types of sexual selection
intersexual
intrasexual
intersexual selection
- between the sex
- females choose the males
- females have less reproductive potential and so it is important that they make the right decision
intrasexual selection
- within the same sex
- males compete with each other to be chosen by females - by impressing or charming them
why did trivers propose the parental investment theory
- males can produce lots of sperm for much of their life but females make a greater investment in offspring
- because of this females choose males that are able to and/or willing to invest in their offspring. these males achieve a higher reproductive success
- as a result of these differences trivers proposed the parental investment theory: women are choosier than men as they are investing more in their offspring
cross cultural research into partner preferences
Buss 1989:
- studied partner preferences in 33 different countries
- 10,000 men and women agd 16-28 were asked about their preferences
- in all cultures her found that men valued physical attractiveness more than women and valued women younger than themselves. women valued financial success and ambition more.
- this research reflect sex differences due to anisogamy and supports predictions about partner preferences from sexual selection theory.
evaluation of cross cultural research into partner preferences
- whilst Buss managed to represent a wide diversity of cultural groups, his sampling techniques varied from country to country.
- this problem may decrease the validity of the research as the lack of consistency in sampling may lead to confounding variables.
- in addition, as the data was collected through self reporting, participants may not be accurate in perceptions of their own behaviour and may have displayed demand characteristics in order to provide researchers with answers they believe they would want.
- this study also do not explain why certain individuals deviate from the results displayed e.g why do some men have a preference for older women.
why is cross cultural research so important in evolutionary psychology
- if similar findings, patterns or trends are found in different areas of the world, it suggests a universality in nature i.e being innate and natural to all humans - supporting evolutionary theory
- if there are differences in behaviour from one place to another, it supports the influence of culture on behaviour, challenging evolutionary theory
sexual selection as proposed by charles darwin
- if a male characteristic enhances reproductive success, it becomes established as a preference among females so males are under pressure to improve on that characteristic
- males with the trait are preferred and the trait is passed on
evidence to refute darwin’s sexual selection ‘theory’
handicap hypothesis - zahavi
- may be true that certain characteristics seem maladaptive but the very fact that their owners present them are still alive and healthy indicates great survival skills
- they’ve overcome a potential handicap (in terms of survival) and so are a ‘good catch’. these exaggerated features/characteristics are a type of ‘fitness indicator’
fitness indicator definition
- anything which suggests presence of good genes, survival skills or parenting potential
fitness indicator issue
- fitness indicators can be faxed
example of honest indicator in humans
- facial symmetry
- psychologically difficult to fake.
- waist-to-hip ratio in famles is another
consequences of sexual selection
- sexual dimorphism
- facial characteristics
- body shape
sexual dimorphism as a consequence of sexual selection
- physical differences between the sexes
- human males are generally larger as it is suggested humans evolved in a polygynous mating system with more intense sexual competition between males than females
facial characteristics as a consequence of sexual selection
- research shows that females with neotenous features are universally thought of as more attractive
- research has shown that males with strong jaws and large noses are more attractive (thornhill and gangestad)
- bruce and young found a preference for symmetrical faces
body shape as a consequence of sexual selection
- singh: found a preference for waist to hip ratio of 0:7. this produces an hour-glass body shape
- preference persists despite a figure being curvier or slimmer
evidence to support partner preferences
Lonely Hearts:
- Dunbar 1995 used 9– personal ads from north American newspapers
- 42% of men wanted a younger partner
- 25% of women wanted a younger partner
- 44% of men sought a physically attractive woman
- 22% of women sought a physically attractive man
mating strategies
monogamy
polygyny
polyandry
promiscuity
monogamy
mates with one partner
polygyny
one man with multiple women
polyandry
one women with multiple men
promiscuity
both partners with multiple partners
study to support differences in reproductive behaviour
- men have more of a tendency to engage in casual sex
clark and hatfield : - strangers of the opposite sex were approached and offered to either go out that night, go back to their house or to have sex with them
- results: 50% of men and women agreed to first
- 69% of men agreed to second but only 6% of women agreed
- 0% women agreed by 75% of men agreed to C
- These results support the theories made about sexual selection (that women are more choosy with their partners as they want men that are willing to invest in their offspring).
evaluation of study to support differences in reproductive behaviour
- norms of sexual behaviour are changing rapidly and evolutionary theories cannot account for these changes
- Bereckej et al argue that women’s participation in the labour market has had consequences for mating preferences which may no longer be resource oriented
- chang compared partner preferences over 25 years and found that some had changed but others remained the same, corresponding with huge social changes in that time