Men appear to be biologically programmed to prevent them from committing adultery with their friends wives/girlfriends.
English Resarchers discovered that the testosterone level of male adults drops when having contact with the wife or girlfriend of a close friend. Probably this has to do with evolution and did it help humans to live in large groups This may be an evolutionary adaptation that in Prehistoric Times helped humans to live in large groups.
Men have many chances to pursue a friend’s wive, but adultery in this cases can be called very rare.
The testosterone level of a man generally increases when they are interacting with a potential sexual partner. But in interaction with the wive or girlfriend of a friend, the respect for their friend seems to keep the upper hand. This may help explain how people manage to cooperate in neighborhoods, cities and even worldwide, the researchers say.
The findings about testosterone levels illuminate how people have evolved to form alliances and allows villages or families to coexist and cooperate in communities.
During evolution, men who constantly betrayed their friends’ trust and endangered the stability of families may have caused a survival disadvantage for entire communities. The lack of trust in these communities would have made them fragile and vulnerable to attack and conquest.