evolutionary theory

• Darwin's theory of evolution , natural selection

  animals should evolve physical & behavioural characteristics that allow them to perform in competition with their rivals , increases their chance of survival
• Darwin's theory of evolution, sexual selection 


  traits could evolve because they were attractive to the opposite sex or increase chances of winning a mate, will lead to survival of their genes due to increased reproductive success
• Darwin's theory of evolution, reproductive success

  number of offspring produced
• 2 process in sexual selection

  intersexual and intrasexual selection
• intersexual selection 


  mate choice, members of one biological sex choose mates of the the other sex, these mate choice preferences cause preferred characterises to survive, as these genes are passed on
• intrasexual selection 


  competition, when members of the same sex, within a species, compete with each other to order to gain opportunities to mate with others
• evolutionary theory of sexual selection

  purpose of attraction is to maximise the chance of passing on genes , so people are attracted to those that will increase their reproductive success. theory predicts a sex difference in mate choice preference and choosiness, as males and females have different biology and therefore had very different strategies for increasing their reproductive success back in EEA
• biological differences


  evolution psychologists argue that men and women will different partner preferences due to biological due to biological differences
• biological differences examples 


  males = large number of sperm and fertile everyday from puberty to death vs females = produce inly a few eggs and only fertile for 72 hours a month from puberty to menopause
• male optimum strategy for reproductive success

  attracted to females who

  are physically attractive

  have symmetrical faces

  are curvy, thin waist = not already pregnant and big buttocks = fat reserves

  are young = fertile

  
  

  choosiness = males will be promiscuous

  as there is a low cost of making a bad choice of mate , have plenty more sperm & opportunities to mate again
• female optimum strategy for reproductive success 


  look for

  resource to look after herself and child

  ambition = will work hard to improve level of resources

  older men = more time to gather resources

  intelligent men = increased chance of finding resources

  choosiness , will be choosy as costs of bad choices are high, due o limited opportunities to reproduce & the greater amount of investment in each child
• supporting evidence of gender differences in mate choice

  buss

  37 cultures , 9ooo + participants completed questionnaire

  asked ps for desired characteristics in a partner

  f valued earning potential

  m valued physical attributes
• weakness of buss 


  fails to distinguish between long term and short term preferences

  studies show people have differences pretences for brief sexual encounter compared with looking for a long term partner

  Kenrick's found that men were not worried about a females intelligence for a one night stand but intelligence was important for marriage

  findidngs were same for females , so findings may not be valid in all situations
• Evidence for men being more promiscuous than women 


  Clack and Hatfield

  college students were approached by a stranger and asked

  -would you go on a date with me

  -would you go back to my apartment —would you sleep with me

  results = sleep with them , m =75% , f=0%
• Reductionist 


  Complex social behaviour of male choice is reduced to a reproductive strategy

  life is simplified to the spreading of genes

  focuses on nature, de-emphasising the role of nurture = biological reductionism

  doesn’t take cultural influences into account

  doesnt consider individual differnces in partner choices
• deterministic 


  if our genes determine our mate choice then it means we would have little to no choice over the matter = biological determinism

  can be socially sensitive, used as an excuse for poor behaviour such as cheating or rape
• intrasexual selection 


  competition within a sex

  males have to compete with each other as females are choosy, therefore females become a limited resource for which males must compete
• sperm competition 


  in animals such as chimpanzees many males mate with each female, o a female may have the sperm of several males within their reproductive tract

  so males have had to adapt to increase the number of sperm in each ejaculation in order to compete with rival sperm
• sperm competition , ao3

  evidence = testes size

  larger testes suggest more sperm so more competition

  testes of humans are larger than gorillas , who live in single male harems, but smaller than chimpanzees, many males mate with same female.