Selfish? Generous? The Brain's Signals Give Clue

By Jane Farrell

Researchers analyzing the brains of women and men found that they respond differently to pro-social and antisocial behavior, depending on the circumstances.

The striatum, located in the middle of the brain, is responsible for the assessment of reward and is active whenever a decision is made. The findings, from the study by researchers at the University of Zurich, show that the striatum was more strongly activated in female brains during prosocial decisions (such as sharing money) than during selfish decisions. By contrast, selfish decisions led to a stronger activation of the reward system in male brains.

However, the investigators also found that the reward system was disrupted by administering medication to the participants. Under these conditions, women behaved more selfishly, while men became more prosocial. The latter result surprised the researchers. The researchers said that this demonstrates that the brains of women and men also process generosity differently at the “pharmacological level.”

Even if these differences are evident at the biological level, the investigators warned against assuming that they must be innate or of evolutionary origin. Investigator Dr. Alexander Soutschek explained, “The reward and learning systems in our brains work in close cooperation. Empirical studies show that girls are rewarded with praise for prosocial behavior, implying that their reward systems learn to expect a reward for helping behavior instead of selfish behavior. With this in mind, the gender differences that we observed in our studies could best be attributed to the different cultural expectations placed on men and women.”