Clark and Hatfield (1989)

• Background

  The study is based on the parental investment theory, which suggests:

  • Women are more selective in mate choice due to higher parental investment
  • Men are more willing to engage in casual sex to increase chances of spreading their DNA
• Aim: 



  To investigate gender differences in attitudes towards casual sex.
• Procedure


  • Two experiments: 1978 and 1982 (replication)
  • Sample: 48 male and 48 female participants in each study
  • Confederates approached strangers of the opposite sex with one of three requests:

  1. "Would you go out with me tonight?"
  2. "Would you come over to my apartment tonight?"
  3. "Would you go to bed with me tonight?"
• Results:

  • About 70% of men were willing to have casual sex in both experiments
  • No women agreed to casual sex in either experiment
  • Attractiveness of the confederate had no significant impact on responses
• Modern Replication (Baranowski & Hecht, 2015)


  • Tested if social setting affected consent to casual sex
  • Conducted on university campus and in nightclubs
  • Found significantly more men than women consented to sexual invitations in both settings
  • In a "safer" lab environment, gender differences disappeared
• Strengths:

  • Replicated results indicate reliability
  • High ecological validity as a field experiment
• Limitations:


  • Ethical concerns due to deception
  • Results may be influenced by social norms and safety concerns, not just evolutionary factors
  • Possible lack of temporal validity due to changes in social attitudes since the original study