Wedekind (1995)

• Aim


  Determine whether one's MHC (Major Histocompatibility Complex) would affect mate choice.
• Participants


  49 female, 44 male students from University of Bern, Switzerland.
• Procedure (men)


  They were asked to wear a t-shirt for two nights and to keep the t-shirt in an open plastic bag during the day. (They were asked not to engage with anything that would affect with their natural scent, eg. drink or smoke)
• Procedure (female)


  They were asked to rank the smell of 7 t-shirts. (This was during the second week after beginning of menstruation - women appear to be odour-sensitive). The women were asked to prepare themselves using nose spray for the 14 days before the experiment).
• Procedure - experiment (female) 


  Women were asked to rank the smell of 7 t-shirts (each in a carboard box). Three of the shirts were from similar MHC men, another three were from dissimilar MHC men, and the last one was an unworn shirt (control). They ranked it for intensity (0-10), pleasantness and sexiness (0-10, 5=neutral).
• Results


  Women scored male body odors as more pleasant when they differed from their own MHC.
• Inference


  MHC influences human mate choice. (Dissimilar MHC, when mated with, will produce a stronger offspring - natural selection).
• Strengths


  Unworn shirt as control, successfully replicated on mice, double-blind experiment, many factors restricted, participants did not know each other.
• Limitations


  Reductionist (mating behaviour is not solely determined by MHC), scoring can be subjective, sample is not representative as they were similar in age and culture (sampling bias).