Geneva, Oct 16 (PTI): Women tend to be more generous than men, as selfish behaviour activates the brains reward system more strongly in men, scientists have found.

Scientists from University of Zurich in Switzerland looked at the areas of the brain that are active when decisions of this kind are made.

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 that 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.

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.

"These results demonstrate that the brains of women and men also process generosity differently at the pharmacological level," Alexander Soutschek from University of Zurich.

The results also have consequences for further brain research, with Soutschek stating that "future studies need to take into account gender differences more seriously," Soutschek said.

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," said Soutschek.

"Empirical studies show that girls are rewarded with praise for prosocial behaviour, implying that their reward systems learn to expect a reward for helping behaviour instead of selfish behaviour," he said.

"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," he added.

This learning account is also supported by findings that indicate significant differences in the sensitivity of the reward system to prosocial and selfish behaviour across cultures.