The more altruistic gender? It depends on how long people have to think about decisions

When asked to make a split-second decision about how to divvy up cash between themselves and a stranger, female subjects in a new study were significantly more altruistic in their decisions than their male counterparts were.

But given time to think about the decision, the outcome changed. Some of the female subjects—particularly those who described themselves as having more traditionally masculine characteristics, like dominance—became just as selfish as the men once they had time to mull over their choices. But women who saw themselves as having more feminine traits continued to make selfless decisions when sharing the money.

The outcome could be explained by society’s gender expectations, argued lead authors David Rand of Yale and Victoria L. Brescoll of the Yale School of Management, in a study published in the Journal of Experimental Psychology.

Altruism by definition is selfless behavior, but not being seen as selfless can have a higher social cost for women. Women perceived as insufficiently generous “are not only liked less,” the authors wrote, “but they are also less likely to be helped, hired, promoted, paid fairly, and given status, power, and independence in their jobs.”

These social risks are so deeply ingrained that most women will revert to those patterns on impulse—even those who don’t view themselves as being traditionally feminine.