A University of Missouri study found that the testosterone
levels of men dropped when they interacted with the wife of a close friend.

What does this mean? Testosterone is the chemical of sexual
desire and aggression in both men and women. Men's T-levels tend to rise when
they're around a potential sex partner -- as well as when they're around the
mate of their enemy. Interesting, no?

Extrapolating, the researchers think that this mechanism may
have evolved to help social cooperation in villages. According to the press
release, Lead researcher Mark Flinn says, "… our findings suggest that
men's minds have evolved to foster a situation where the stable pair bonds of
friends are respected. … Ultimately, our findings about testosterone levels
illuminate how people have evolved to form alliances. Using that biological
understanding of human nature, we can look for ways to solve global problems."

The study "Hormonal
Mechanisms for Regulation of Aggression in Human Coalitions" was
published in the journal Human Nature. Co-authors were Davide Ponzi of
MU's Division of Biological Sciences in the College of Arts and Science and
Michael Muehlenbein of Indiana University.

Photo: Steve Rhoades