evolutionary explanations for partner preferences Flashcards
what is the idea of sexual selection
the selection of characteristics that aid successful reproduction(rather than survival)
selection for females
chooose males with particular characterises to produce robust offspring perpetuated in future gens
adaptive characteristics for males
-e.g aggressiveness bc they provide advantage for a male over competitive reproductive rights
-aggressiveness passed to offspring and helps to remain in the population
what is natural selection?
-Darwin survival of the fittest
what is sexual selection?
-attributes or behaviours increasing reproductive sucess are passed on and become exagerated over time
what is human reproducitve behaviour?
-behaviours allowing them to reproduce and increase survival chances of our genes
what anisogamy
-refers to differences between male and female gametes
what are male gamete like
-small
-highly mobile
-unlimited supply
-don’t neeed much energy to be produced
what are female gametes like
-large
-static
- produced at intervals
-limited fertile years
-a lot of energy required
what is one consequence of anisogmay
-no shortage of fertile males but a fertile female is much rarer resource
-ansiogamy is importsnt in partner preference because it gives a rise to two types of sexual selection
what is inter sexual selection
-between the sexes - strategies that males use to select females or strategies used by females to select males
-female values quality of quantity
what was trivers theory on inter sexual selection
-females make greater investment of time commitment and other resources before, during and after birth offspring
-both sexes are choosy
-but female is more choosy due to the consequences of choosing wrong partner
-female wants genetically fit partner who can provide
what’s an example of trivers theory
-if height was attractive male trait by females then it would increase in the male pop over successive generations
(females will always select the tallest males then characteristic becomes exaggerated)
- a runway process
what was ronald fishers sexy son hypothesis
-female who mates with a male who has a certain characteristic then will have sons with a ‘sexy trait ‘
-her sons are more likely to be selected by successive generations of females who will mate with her offspring
why is sexual selection important for males
-males produce sperm in thousands (quick and easy)
-so they want to mate w many females bc this results in max number of offspring.
what is intra sexual selection
-within each sex
-strategies between males to be the one selected
-male prefer quantity over quality
-competition between males to be the one selected by a female
- characteristics that contributed to his victory of being chosen go to his offspring
what has the strategy led to
-sexual dimorphism
-males and female therefore end up looking for very different
- larger males more advantaged and more likely to reproduce
- for females youthfulness is selected bc males prefer to mate w younger and fertile women
what characterises are favoured that allow males to outcompete their rivals
-deceitfulness
-intelligence
-aggression
can acquire fertile female and protect them
positives
(research support for inter sexual)
- clark and hatfield= sent female and male psych students across a uni campus
-approached student w question of “ i’ve been noticing you around campus i find you very attractive would you to bed with me”
-not a single female agreed to the request whereas 75% of males did
-supports view females are choosier than males but males want to ensured reproductive success
(research support for intra sexual )
-Buss = carried out a survey on over 10,000 adults in 33 countries
-he found females placed greater importance resource related characteristics e.g good financial prospects and ambition
-males wnated physical attractiveness and youth as signs of fertility
- support predictions. from sexual selection theory
weaknesses
(counterpoint for research support for inter sexual selection)
-BUSS AND SCHMIDT argue that both females and males adopt similar mating strategies when seeking long term RS
-very choosy and look for partners who are loyal,loving, kind
-theres a more complex view of how evolutionary pressures infulence partner preference
-one off sexual partners also dont guarntee males will pass their DNA, regular intercourse throughout month increases likelihood of fertalisation.
(social and cultural infulences underestimated)
-theres rapidly changing norms and values
-changes may have occured due to cultural factors e.g contraception available
-woman have greater role in work place done depend on men.
-Bereczkei=social change has consequences for women preferences- may no longer be resource oreintated
-pereferences today are likely evolutionary and cultural but the theorys explanation is limited.
(sexual selection and homosexuality)
-cannot explain partner preferences of gay and les
-homosexual RS may not asess genetic fitness but perhaps qualities like caring for offspring
-Lawson et al -studied personal ads and found variety between homosexual and heterosexual woman and men
-alot of ‘romance’ comes down to individual differences
more supporting points
(support from lonely hearts research)
-WAYNFORTH and DUNBAR= studied lonely hearts in american newspapers
-woman offered physical attractiveness and indicators of youth(flirty, exciting,sexy , curvy)
-men offered resources and sough youth
more weak evaluation
(gender bias)
-men presented as sexually promiscous not always the case tho
-ignores benefits of promiscuity for females(produce better quality offspring)
(biological reductionism)
-evolutionary factors overemphasised
-choosing partner in modern society is more than about reproduction
(self report studies and valdidity)
-focused too much on reported preferences rather than IRL choices
-lacks validity
-preferences dont predcit IRL outcomes
-what we say we like vs what we find attractive contradict.
what was the waist-hip research?
-men prefer female body shape that signals fertility
-SINGH(2002)= found generally a ratio from around 0.7 was found to be attractive
-wider hips, narrow waist signaled fertility
how can we evaluate the spice finch?
-its monomorphic(exists in only one form- little variation
-blows darwins theory of sexual selection
