In the eyes of men, manhood is an elusive quality: easy to lose and hard to regain. And aggression is a prime tactic used when a attempting to regain it.

In a trio of tests, psychologist Jennifer K. Bossson, Ph.D. gave men the decidedly unmanly task of braiding hair and recorded its effects on them.

Men were offered the choice of punching a bag or doing a puzzle. The hair braiders overwhelmingly opted for the punching bag.

In the first test, half the men braided hair, while the other half did the more gender-neutral, less threatening task of braiding rope. Afterwards, the men were offered the choice of punching a bag or doing a puzzle. The hair braiders overwhelmingly opted for the punching bag. In a similar test, some men braided hair and others did not. Afterwards, all were told to punch the bag. The men who had braided hair punched harder.

Finally, a test was set up where all the men braided hair. Afterwards, only some were allowed to punch the bag. When then given an anxiety test, the non-punchers tested as more anxious.

To Dr. Bosson, an associate professor of psychology at South Florida University, this adds up to hair braiding threatening masculinity and aggression helping to restore it or at least the feeling of it.

In related study she attempted to reveal some of men's inner thinking on manhood. Both men and women were given mock police reports where either a man or woman hit someone of their own sex after being taunted about their manhood (or womanhood). The subjects were then asked their thoughts about the attacker's motivation.

When the attack was between women, both male and female subjects attributed it to character traits, such as immaturity. When the attack was between men, the woman participants still attributed it to character traits. But the male participants tended to say that the aggressor was provoked and the attack stemmed from him defending his manhood.

Bosson takes this as evidence that it is men, not women who are preoccupied with manhood and such tough judges of its lack or loss.

By this type of thinking, women are born female and can only lose their femininity by biological processes such as menopause. For them, gender is essentially biological. But men can lose their manhood through their actions (such as hair braiding) — their gender has a social component every bit as important as the biological one.

Studies like these have changed how Dr. Bosson views men. "When I was younger I felt annoyed by my male friends who would refuse to hold a pocketbook or say whether they thought another man was attractive. I thought it was a personal shortcoming that they were so anxious about their manhood. Now I feel much more sympathy for men."

An article on the studies appears in the April 2011 issue of Current Directions in Psychological Science.