The women are more generous than men, have shown that behavioral experiments done so far. Now a team of researchers at the University of Zurich (Switzerland) has shown that female and male brains process prosocial and selfish behavior differently. For women, prosocial behavior triggers a stronger reward signal, while male reward systems respond more strongly to selfish behavior. This is the first study to show that the brains of men and women respond differently to prosocial and selfish behavior.
In a double-blind experiment designed to identify whether differences in brain chemistry could help explain generosity, scientists restricted dopamine receptors (which help communicate pleasure and reward) in a group of 55 volunteers ( 27 women and 28 men) and observed their brain reaction by giving them a sum of money. Specifically, the volunteers were randomized into two groups before injecting either the dopamine sipresor or the placebo.
They then had to perform two tasks. First, they could choose two possibilities: to keep a large amount of Swiss francs in hand or to obtain a smaller reward shared with a friend or with the group. In the second task, the participant was offered between a small reward now and a greater reward if he waited 90 days. Once evaluated, the two groups were exchanged.
When taking placebo, the women in the study chose to share with others 51% of the time. Men, on the other hand, did this on just 40% of the occasions. With the dopamine blocker, women reduced this percentage to 45%. The men were slightly more prosocial without the dopamine, because they shared their money with the others in the 44% of the times.
The study indicates that in a gender division of male or female participants, there may be differences as to the neurotransmitter that pushes them to be a little more loving and generous.
It is unclear whether this difference drawn from the study could emerge from variations in our chromosomes, or whether it is a behavior learned and forged by decades of social conditioning.
In addition, a group of 55 people is also a fairly small sample size, and the differences – although interesting – were not exactly overwhelming.
Despite this, the conclusions raise some fascinating questions about the limits of decision-making and the influence of gender. Throughout history, scientists have debated the characteristics that separate men and women and wondered how much of them belong to nature itself and how much is subject to change. Experiments like this offer tools to study the neurochemistry behind pro and antisocial behaviors, so that we can soon better understand the subtle interactions of genetics, culture, and anatomy.