evolutionary explanation for partner preferences

• sexual selection

  attributes or behaviours that increase reproductive success are passed on and may become exaggerated or more common over time
• Anisogamy

  differences between males and female sex cells
• Female sex cells

  • static
  • limited years of fertility
  • larger
• Male sex cells

  • smaller
  • extremely mobile
  • infinite supply
• Two types of sexual selection:

  • intersexual selection: what one sex looks for in the other
  • intrasexual selection: how members of the same sex compete to mate with members of the opposite sex.
• Males want women to have

  • 0.7 waist to hip ratio
  • babylike face
  • fertility
• Females want men to be:

  • tall
  • strong
  • caring
• Trivers (1972)


  claims that females hold greater importance in time, commitment, and resources than males because making the wrong choice in a partner is more serious due to their fertility window.
• Fisher (1930)

  • developed the sexy son hypothesis
  • the genes that are prevalent today are determined by reproductive success
  • women select men who have certain traits whose sons will inherit this sexy trait and pass it onto the future generation.
• Intrasexual selection

  • men need to be bigger and stronger to have an advantage and to be more likely to mate
  • women need to look younger to appear more fertile
  • can have behavioural consequences in men such as aggression (to protect women from other men) and intelligent to find ways to win women over.
• Support for intrasexual selection

  A strength of intrasexual selection is Buss's research, showing that females value resources like ambition, while males prioritise youth and attractiveness, highlighting consistent sex differences in sexual selection.
• support for intersexual selection

  Clark and Hatfield found that 75% of men agreed to casual sex, while 0% of women did. This suggests women prefer getting to know partners, while men are more open to casual sex due to lower commitment.
• counterpoint

  The Clark and Hatfield study is too simple, as preferences change with relationship seriousness. Buss and Schmitt suggest both sexes seek traits like loyalty in long-term partners, showing sexual selection varies with individual differences.
• social and cultural factors

  A limitation is that evolutionary theory overlooks social and cultural factors. As women have become more independent, partner preferences now reflect both evolutionary and cultural influences, making the explanation incomplete.