Via ScienceDaily:
After outgrowing teenage infatuations with the girl next door, adult males seem to be biologically designed to avoid amorous attractions to the wife next door, according to a University of Missouri study that found adult males’ testosterone levels dropped when they were interacting with the marital partner of a close friend. Understanding the biological mechanisms that keep men from constantly competing for each others’ wives may shed light on how people manage to cooperate on the levels of neighborhoods, cities and even globally.
“Although men have many chances to pursue a friend’s mate, propositions for adultery are relatively rare on a per opportunity basis,” said Mark Flinn, professor of anthropology in the College of Arts and Science. “Men’s testosterone levels generally increase when they are interacting with a potential sexual partner or an enemy’s mate. However, our findings suggest that men’s minds have evolved to foster a situation where the stable pair bonds of friends are respected.”
Flinn says that these findings might help solve global problems.

