Biological Approach: Evolutionary Psychology

Question 1

What is evolutionary psychology grounded in?

Answer 1

• evolutionary psychology is grounded in the theory that as genes mutate, those that are advantageous are passed down through a process of natural selection
• natural selection cannot select for behavior; it can only select for the genes that may produce behavior
• an assumption made by evolutionary psychologists is that behaviors are genetic and may be inherited

Question 2

What is natural selection?

Answer 2

• those who adapt best to the environment will have a greater chance of surviving, having children, and passing on their genes to their offspring

Question 3

Wedekind (1995) can be used for…

Answer 3

• evolution and pheromones

Question 4

Wedekind (1995) - aim

Answer 4

• to determine whether one’s MHC would affect mate choice
• MHC (Major Histocompatibility Complex) is a set of genes responsible for our immune system

Question 5

Wedekind (1995) - procedure

Answer 5

• men were asked to wear a T-shirt for 2 nights and to keep the T-shirt in an open plastic bag during the day
• they were given perfume-free detergent to wash clothes and bedclothes and perfume-free soap for showering
• they were asked not to use any deodorants or perfumes, to refrain from smoking tobacco or drinking alcohol, to avoid all spicy foods, and to not engage in any sexual activity
• 2 days later, the women were asked to rank the smell of the 7 t-shirts
• women were tested in the 2nd week after the beginning of menstruation, as women appear to be most odor-sensitive at this time
• women were also asked to prepare themselves for the experiment by using a nose spray for the 14 days before the experiment to support the regeneration of the nasal mucous membrane
• each woman was given novel perfume to sensitize their smell perception
• 3 of the 7 boxes contained T-shirts from men with MHC similar to the woman’s own; 3 contained T-shirts from MHC dissimilar; and 1 contained an unworn T-shirt as a control
• alone in a room, every woman scored the odors of the T-shirts for intensity, pleasantness and sexiness (range 0-10)

Question 6

Wedekind (1995) - findings & conclusion

Answer 6

• women scored male body odors as more pleasant when they differed from their own MHC than when they were more similar
• this difference in odor assessment was reversed when the women rating the odors were taking oral contraceptives
• this suggests that the MHC may influence human mate choice