evolutionary explanations for partner preference Flashcards
what is sexual selection?
it explains the evolution of characteristics which enable reproductive success rather than survival success
what is reproductive success?
characteristics that are attractive to the opposite sex and enable us to successfully reproduce
what is anisogamy?
- the differences between male and female sex cells
- never a shortage of fertile males but female fertility is a ‘resource’
- in terms of , partner preferences, this leads to differences in sexual selection and mating strategies
gametes
- sperm (males) are small, and produced in vast quantities over the males life and do not require much energy to produce
- eggs or ova (female) are relatively large, produced at intervals for a limited period of time and require a great deal of energy
intrasexual selection
- when members of one sex (usually males) compete with each other for access to members of the other sex. – the victors are able to mate and so will pass on their successful characteristics (taller and stronger)
- given minimal energy required for males to reproduce and lack of reproductive consequences, the male’s optimum strategy is to compete in order to reproduce with as many fertile females as possible (quantity over quality)
dimorphism
- the obvious differences between males and females
- physical competition between males favours men being taller and stronger, which is passed on
- females don’t compete for males in the same way and therefore haven’t developed this characteristic - however looking youthful is a fertility signal
- this means they are more likely to be selected for mating, which is then a characteristic passed on to offspring
intersexual selection
- between the sexes - the strategies that males use to select females or that females use to select males.
- females use more of a strategy of ‘quality over quantity’ because of the commitment females need to invest in offspring before, during and after birth and the ore serious consequences of choosing the wrong male, it pays for females to be choosy when selecting the right mate
- e.g only choosing males with characteristics that enable them to provide resources and protect her and her offspring (hard working, intelligence)
what does intersexual selection determine?
what characteristics are passed on to offspring and which develop in a population. for example, fisher’s sexy sons hypothesis says that a female mates with a male who has a desirable characteristic, and this ‘sexy’ trait is inherited by her son. this increases likelihood that future generations of females will mate with her offspring
what is the research support for intersexual selection by clark and hatfield (1989)?
-male and female psychology students approached other students on campus ‘would you go to bed with me tonight?’
-found not a single female agreed, but 75% of the males did, immediately
- suggests that males have evolved a different mating strategy to females in order to ensure maximum reproductive success and that women are indeed more choosy when selecting a mate, as predicted by evolutionary theory
what is further research support done by waynforth and dunbar (1995)?
- studied lonely hearts advertisements in american newspapers
- like modern day dating apps describe what they are looking for and what they have to offer
- found that women more than men tended to offer physical attractiveness and indicators of youth (flirty, curvy, sexy)
- men offered resources more than women (successful, mature, ambitious) and were looking for relative youth and physical attractiveness
- supports evolutionary theory’s prediction that females will prefer females who have indicators of fertility
what is a limitation of evolutionary explanations?
- the theory is outdated
- women now have a greater role in the workplace and are no longer dependent on men to provide for them
- Bereczkei (1997) argue that this social change has consequences for mate preferences, which may no longer be resource-orientated
- problem as partner preferences may be more likely to be a combination of cultural and evolutionary influences and any theory failing to account for both is limited
