A Discussion of Wedekind's Mate Selection Factors

(SAQ) Explain one evolutionary explanation of one behavior

The aim of this SAQ is to give a detailed account of mate selection as explained through evolutionary terms by the study of Claus Wedekind (1995). For everything psychological there is a biological change linked to it. Evolutionary psychology is a branch of biopsychology focusing on the functional value of behaviors that allowed humans to survive across generations. It is heavily based on Darwin’s theory of evolution about natural selection were organisms that adapt best on environmental demands, mutate and increase their chances of survival compared to others (survival of the fittest). In his controversial book “The Decent of Man” Darwin argued that organisms procreate to pass on their genes to the next generation through sexual selection, either becoming more attractive to the opposite sex or intimidating same-sex rivals. According to evolutionary psychology, mate selection in humans serves the functional value of reproduction and offspring and undoubtedly the parental investment is heavier for females as they have to go through pregnancy and lactation. It has been widely reported that body smell is one trait that humans find attractive in potential and actual mates. Evolutionary psychologists have questioned if smell could be assigned of genetic diversity that may increase their off springs immunity, especially for females.

Claus Wedekind is a Swiss biophycologist that studied the MHC which stands for major histocompability complex. MHC is a group of genes related to the development of our immune system and we inherit our MHC from both our parents equally. Biophycologists argue that smell is a sign of out MHC. One more thing is that the more dissimilar the MHC is between the parents the healthier the offspring. In order to test that, Claus Wedekind conducted the following experiment. He got a sample of 49 females and 44 males from the university of Bern, in Switzerland. Each participant was DNA tested to check their MHC and the result showed a wide variety of MHC categories. In order for this experiment to be valid the experimenter had to use some controls. First of all, he used a double-blind technique so either the experimenter nor the participant knew the real reason for the study. Another control was the fact that it was noted down if the female participants were taking contraceptives that affect hormones. Lastly, he used students with no previous contact so the smell would not be familiar.

Then, he began his experiment. He asked the male participants to sleep with a cotton shirt for two nights and keep it in a plastic bag during the day. The participants were not allowed to use perfume or deodorant and they were given odor free shampoo in order not to affect their smell. Then, t-shirts were put in identical cardboard boxes with a hole in them for the female participants to smell from. Each female had to smell each shirt and rate them from 1-10. The shirts were allocated with the following patter; 3 out or seven had similar MHC with the female, 3 out of 7 had dissimilar MHC with the female and the last one was a control and it was not worn by anyone. Women if possible were tested in the 2nd week of their menstrual cycle, the most odor sensitive period, and to prevent potential flues and to help regenerate the nasal mucous membrane the females were given a nasal spray to put for 14 days before the experiment was conducted.

The finding of the experiment showed that women preferred males with dissimilar MHC that them, but the opposite occurred for women on their pill. Also, the odors of MHC dissimilar men reminded the women of ex partners more that the MHC similar men. The conclusion from all these findings is that MHC or linked genes affect human mate selection.