Researchers identify "male warrior effect"

NORWICH (Reuters) - Men may have developed a psychology that makes them particularly able to engage in wars, a scientist said on Friday.

New research has shown that men bond together and cooperate well in the face of adversity to protect their interests more than women, which could explain why war is almost exclusively a male business, according to Professor Mark van Vugt of the University of Kent in southern England.

While the theory makes sense to me, the study is a little abstract:

In experiments with 300 university men and women students, Van Vugt and his team gave the volunteers small sums of money which they could either keep or invest in a common fund that would be doubled and equally divided. None of the students knew what the others were doing.

Both sexes cooperated in investing in the fund. But when the groups were told they were competing against other universities, the males were more eager to invest rather than keep their money while the number of women contributing remained the same.

Extrapolating a male warrior effect is consistent with the findings, but is a bit of a stretch given the nature of the study.