There is pleasure in both giving and receiving. Does gender influence which of these pleasures we prefer?
In women, part of the brain showed a greater response when sharing money, while in men, the same structure showed more activity when they kept the cash for themselves, a small study published Monday in Nature Human Behavior found.
Women tend to be more altruistic than men, previous studies have shown. As Philippe Tobler, co-author of the new study, sees it, “women put more subjective value on prosocial behavior and men find selfish behavior more valuable.”
“However, it was unknown how this difference comes about at the level of the brain,” Tobler, an associate professor of neuroeconomics and social neuroscience at University of Zurich, wrote in an email. “But in both genders, the dopamine system encodes value.”
By “encode,” he means the activity in our brain changes in proportion to the value we give social experiences.
Searching for answers for why women and men are not equally selfish, he and his colleagues focused on the dopamine system.
Dopamine, which plays a fundamental role in the brain’s reward system, is released during moments of pleasure, yet it also helps us process our values. This mental ability transpires within the brain machinery known as the striatum. Latin for “striped,” the striatum is threaded with fibers that receive and transmit signals from the cerebral cortex, the thalamus and other brain regions.
Tobler and his colleagues designed a series of experiments to test how dopamine might influence the behavior of men and women. Fifty-six male and female participants made choices between sharing a financial reward with others or keeping the money for themselves.
Given only a placebo before making decisions, women acted less selfishly than men, choosing to share their money with others. However, when their dopamine systems were disrupted after they received a drug called amisulpride, women acted more selfishly, while men became more generous. Amisulpride is an antipsychotic normally used to treat the symptoms of schizophrenia. “Based on the opposing priorities of the genders, interfering with the dopamine system has opposing effects,” Tobler said.
In a second experiment, the researchers used functional MRI to investigate changes in the brain while eight female and nine male participants made choices. Compared with the males, the striatum in females showed more activity when they made a prosocial decision.
According to Anne Z. Murphy, an associate professor of neuroscience at Georgia State University, other research has shown “that females are more prosocial. We find it more rewarding, and if you manipulate dopamine signaling in the brain, you can make females less prosocial and males less selfish.” Murphy was not involved in the study.