Evolutionary explanations for behaviour

Behavior can be explained in terms of adaptation and survival advantages, often shaped by natural selection. Behaviors that increase reproductive success are more likely to persist.

attraction/human mate preferences

Humans may have evolved to have Mate choice be influenced by genetic compatibility, detectable via pheromones, to increase offspring immune system diversity.

Major Histocompatibility complex is a set of genes involed in immune system function that influeces oder (phermones)

Wedekind et al 1995

to investigate whether differences in the major histocombatibility complex (MHC) genes influece human mate preference

double-blind, quasi experiment
Used 49 female students and 44 male students (from different courses of the same university)
the participants were examined to establish their MHC types.
the women were asked to report if they consumed oral contraceptives because it may affect the perception of those women
the men were provided with a clean new 100% cotton t-shirt and were asked to wear it for two nights under controlled conditions (keeping it in a plastic bag when not wearing it, no perfume, spicy food, etc)
Female paritcipents then smelt the shirts and rated them on scale of 7 for intesnity and pleasentness
the shirts were:
MHC similar to female paritcipents
MHC dismilar to female participents
the testing was timed to the second week of the woman's menstrual cycle (most smell-sensitive)

Women generally rated the shirts with MHC dissimilar to them higher in pleasentness than the MHA similar to them
When women were on contreptives it was the oppsite

Body odor likely contains pheromone-like chemical signals reflecting genetic makeup.
These signals subconsciously influence perceived attractiveness.

This behavior supports evolutionary theory by favoring mates with different immune systems, enhancing offspring survival, and proving that mate selection is driven by biological fitness