Behavioral experiments have shown that when women share a sum of money more generously than men. To gain a more in-depth understanding of this behavior, neuroscientists from the Department of Economics looked at the areas of the brain that are active when decisions of this kind are made. They are the first to demonstrate that the brains of men and women respond differently to prosocial and selfish behavior.
Selfish behavior activates reward system more strongly in men
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 show: The striatum was more strongly activated in female brains during prosocial decisions than during selfish decisions. By contrast, selfish decisions led to a stronger activation of the reward system in male brains.
Disrupted reward system leads to more selfish behavior in women
In the second experiment, 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. As Soutschek explains, "these results demonstrate that the brains of women and men also process generosity differently at the pharmacological level". The results also have consequences for further brain research, with Soutschek stating that "future studies need to take into account gender differences more seriously".
Culturally conditioned behavior patterns are decisive
Even if these differences are evident at the biological level, Soutschek warns against assuming that they must be innate or of evolutionary origin. "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." This learning account is also supported by findings that indicate significant differences in the sensitivity of the reward system to prosocial and selfish behavior across cultures.
Dr Alexander Soutschek
University of Zurich,
Department of Economics,
Blümlisalpstrasse 10, 8006 Zurich
Nature Human Behaviour