RELATIONSHIPS- sexual selection Flashcards
who thought of sexual selection?
darwin
what did darwin say about sexual selection?
species do not just evolve through natural selection but also through sexual selection
what is sexual selection-darwin?
a view that competition for mates between individuals the same sex affects the evolution of certain traits
what is s.s?
any physical trait that enhances reproductive success will gradualy be passed down and enhanced over evolutionary time
what did darwin propose?
animals possess features that make them attractive to opposite sex and allow them to compete better with members of same sex
example of darwins proposal? & who said it ?
pagel et al
relative hairlessness of human beings being compared by great apes feature allowed not only to keep cool but to advertise good hygiene.
what does this example explain?
trait is desirable in sexual selection. greater loss of body hair in women would been through greater pressures on women from s.s. in comparison to men
what about the peacocks tail?
peacocks tail goes against as offers no advantage. it is heavier more noticable by predators and dont help fly better
what did zahavi propose?
proposed “handicap principle” in support of s.s
what did handicap principle state?
if any indicator too costly to produce and still displayed=sign of good genes and health as peacocks able to portray bright feathers and still survive= more attractive to females and such rules apply to humans
what also happens between male and female for s.s.?
different s.s pressures occurs between genders due to differences in gametes (eggs+sperm)
what about females for the different pressures?
limited no. eggs each representing huge investment during and after preg but certain of paternity. due to this must be choosy finding strong healthy males with resurces
what about males for the different pressures?
natural selection favours them maximising paternity opportunities. have millions of sperm h.w can never be certain of paternity and suffer little cost to reproduction
what are the 2 types of s.s that take place in human reproductive behaviour?
intrasexual & intersexual
what does intrasexual occur in?
males who compete with each other 4 access to females
what is intrasexual as a consequence of this?
as consequence men have evolved indicators to show strenghth and testosterone that women seek
examples of males evolved indicators for women?
strong jaw, high cheek bones, triangular backs and wide shoulders
intrasexual- what can high levels of test do?
high levels of testosterone can damage immune h.w displayed in strong male (handicap principle)
what did thornhill et al say? (intrasexual)?
found women prefer males with traits suggesting indicators of s.s for humans. men on other hand look for signs of fertlity , think youth and physical attraction as maximises reproductive success for them
what does intersexual occur in?
women who then go to select men who show best indicators of providing right genes for offspring,ability to protext her & child and status and resources
what do psychologists propose?
it is evolutionary b that then shapes mates selection in males and demales.
what should males look for in theory in contrary to psychologists for evolutionary b?
fertility,youth,physical att
what should females look for in theory in contrary to psychologists for evolutionary b?
strength,masculinity,able to provide and protext
what is the research for s.s?
buss et al
dumber et al
thornhill et al
singh et al
what did buss et al do?
conducted cross cultural study over 37 cultures w/over 10,000 people on mate preference. males reported to prefer younger physically attractive females & females= physically strong & athletic ones w emphasis on resources. both engaging on b of reproductive process
does buss et al support s.s?
yes
critiscms of buss et al study?
q used easily misunderstood across cultures
self reports=inaccurate s well as translation problems occuring through 3rd part translations
mate pref may not be indicative of what happens in real life
what did dumber et al do?
look at 4 american newspapers w over 900 personal ads reviewing mate preference. women offered youth and physical and financial status & resources
does dumber et al support s.s?
yes
critiscm of dumber et al?
based on americans (cultural bias)
in addition kindness and intell rated higher importance for both sources.
what did thornhill et al do?
found symmetrical faces were sought by both genders and symm= strong genetic fitness and strong resistance. women also sought men w masc features while men on women with childlike feat - indicate youth and fertility. both genders engage in b in these studies that increase reproductive success
does thornhill et al support s.s?
yes
what did singh et al do?
found men preferred waist to hip ratio 0.7 across cultures. typical hourglass and a sign of fetility
does sign et al support s.s?
yes
eval of s.s theory? (1)
beneficial as helps to understand human b as some things may be biologically programmed due to nature than nurture and sheds light on mate pref
eval of s.s theory (2)?
although show culture pref of individ, not representative of what acc happens in real life could be social/cultural factors playing role aswell as opportunites avail for both genders within social circle which not factored in.
eval of s.s theory (3)?
gender bias, assume men likely to cheat on partners due to genetic programme. not possible for men without willing women . also cant explain why women cheat and goes against ideal strat of a mate provide support long term.- cuckoldy providing as possible reason = not scientific as based on reason.
s.s eval number 3 also?
post hoc and difficult to post hoc evidence- s.s theory cannot be proven /disporven either way.
what did popper argue no.3 eval?
unscientific theories= purely speculative
s.s eval number 4?
evolutionary theories can be argued as reductionist as simply mate choice down to genetic makeup. partner choice= more complex such as cultural/sociely. this theory driven by nature.
s.s eval number 5?
deterministic as suggests human s.s prefernces=genetically programmed not take into account ability of concious though which gives free will to make choices ourselves.
