Researchers identify a “male warrior effect” — which doesn’t seem very war-like at first:
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.
“We all know males are more aggressive than females,” Van Vugt said, adding that co-operation is needed to establish institutions and governments and to wage wars.
“Male co-operation is a double-edged sword,” he added.