Sexual selection

• Sexual selection

  evolutionary explanation of partner preference

  behaviours + attributes that increase reproductive success are passed on
• Human reproductive behaviour

  Behaviours related to the opportunity to reproduce and so increases survival chances of genes
• Anisogamy

  Differences between male and female sex gametes

  Males= small , high in numbers

  Females= large , limited in numbers

  Consequence of anisogamy = gives rise to different mating stratergies
• Inter - sexual selection

  Selection of mates between sexes

  Female strategy - quality over quantity

  Females make greater investment of time , resources during + after birth

  so need to be choosier to pick male who will give healthy offspring

  Preferred attributes are passed onto offspring
• Intra - sexual selection

  Selection of mates within sexes

  Male strategy - quantity over quality

  Competition to pass on genes to offspring as females are limited resource and are choosy
• Strength of sexual selection : intra sexual

  • Buss - surveyed 10000 ppl in 33 countries (no culture bias) about partner preference
  • Found females value resource related characteristics whereas males valued reproductive capacity
  • Supports sex differences due to anisogamy + partner preferences (sexual selection theory)
  • questionnaire = social desirability bias
• Strength of sexual selection : inter -sexual

  • clark + Hatfield sent students to others to ask them for 1 of 3 things; to go on a date, to go back to their apartment, or to go to bed with them.
  • 75% of males agreed to last question no females agreed
  • Supports female choosiness + how males have evolved different strategy to ensure reproductive success
• Limitation of sexual selection : ignores social + cultural influences 


  • Chang et al report that some preferences have changed and some stay same for over 25 yrs in china
  • Don’t take into account that women are more career oriented so not look for partner - doesn’t apply to modern society
  • Gender bias = promote traditional views of what are ‘natural’ male and female roles and behaviors.
  • suggests need cultural + social influences in explaining human reproductive behaviour
• Grenade

  Gender bias

  • exaggerates differences in what males + females look for in a potential partner- alpha bias
  • differences between males and females may be overstated
  • argue that males + females look for similar characteristics, such as loyalty and kindness