Men enjoy revenge more than women do

Men get greater satisfaction than women from seeing someone they dislike suffer pain, according to a study of how people react when witnessing revenge.

Scientists found highly significant differences between the two sexes in terms of how the male and the female brain responds to acts of retribution.

Both men and women feel empathy towards people they know experiencing pain but in men the empathy turns to pleasure when the victim is someone they dislike.

A team of researchers from University College London said that the findings are the first scientifically based evidence to suggest there is male schadenfreude - a feeling of pleasure at seeing revenge exacted.

Tania Singer of the Wellcome Department of Imaging Neuroscience used brain scanners to show that regions of the brain get activated when a person feels empathy for someone else suffering pain.

Her latest study, published in the journal Nature, attempted to explain whether this was simply an automatic response to seeing someone in pain or whether it can be affected by whether the victim is liked or disliked.

The scientists set up an experiment involving 32 male and female volunteers who were asked to play a game involving financial investments.

However, unknown to the volunteers, four of them were actors who deliberately played an unfair game by consistently sending very little money back to the other players - which made them unpopular.

"During breaks in the tests you could tell from the body language that both the male and female volunteers did not like the actors who had cheated them.

They tried to stay away from them as much as possible," Dr Singer said.

During the second part of the experiment each volunteer witnessed the application of mild electric shocks to the "fair" and "unfair" players while being monitored by a brain scanner.

When the fair players received the shock, which was equivalent to a short bee sting, both the men and the women showed empathy - the empathy-related areas of the brain, the fronto-insular and anterior cingulate cortices, lit up in the scanner.

Women continued to display some degree of empathy when an unfair actor was given a shock but the men showed no activation of the empathy-regions of the brain and in fact experienced a surge of activity in the "reward" or pleasure part of the brain.

Dr Singer said these emotional responses were later confirmed in questionnaires completed by the volunteers when they were asked to judge the actors.

"They consistently rated the fair player as being more agreeable, more likeable and even more attractive than the unfair actor," Dr Singer said.

The scientists believe that the findings may indicate fundamental biological differences between the sexes that may have its roots deep in evolutionary history.

Men and women both sympathise when others suffer pain, but men appear to have a greater predisposition towards wishing those who are unfair being punished.

"This type of behaviour has probably been crucial in the evolution of society as the majority of people in a group are motivated to punish those who cheat on the test," Dr Singer said.

"This altruistic behaviour means that people tend to protect each other against being exploited by society's free-loaders, and evolution has probably seeded this sense of justice and moral duty into our brains," she said.

"We need to confirm these gender differences in larger studies because it is possible the experimental design favoured men as there was a physical rather than a psychological or financial threat involved.

"However, this investigation would seem to indicate there is a predominant role for men in maintaining justice and issuing punishment," Dr Singer said.

- INDEPENDENT