Social rejection affects the brain just like a physical injury

October 16, 2003

Poets have written at length about the pain of a broken heart, and from childhood on we talk about others having hurt our feelings.

Using these physical metaphors to describe our emotions turns out to make sense, say researchers who have found that social rejection really does hurt.

By studying young people who were distressed at being excluded from a game, an international team of psychologists that includes Professor Kipling Williams of Macquarie University has found that two key areas of the brain respond to the pain of rejection in the same way as physical pain.

"While everyone accepts that physical pain is real, people are tempted to think social pain is just in the head," says another team member, Matthew Lieberman, of the University of California, Los Angeles. "But physical and social pain may be more similar than we realised."

Humans are a gregarious lot and, in an evolutionary sense, much of our success as a species is due to our ability to co-operate with each other.

The psychologists believe the pain of being rejected evolved because social bonds are so important for a person's survival.

"Going back 50,000 years, social distance from a group could lead to death - and still does for most infant mammals," says Lieberman. "We may have evolved a sensitivity to anything that would indicate that we're being excluded. This automatic alarm may be a signal for us to re-establish social bonds before harm befalls us."

When people do become socially excluded for a long time, not surprisingly it can have a highly detrimental effect on mental wellbeing.

Associate Professor William von Hippel, a University of NSW psychologist who is helping Williams organise a conference on the issue, says that in a troubled world it is more important than ever to learn more about the causes and effects of social rejection.

Excluding people can increase their risk of depression, suicide and associating with fringe groups, which can draw them into anti-social behaviour.

It can even lead to mass killings. Not everyone who is socially excluded becomes violent, says von Hippel, "but school shootings . . . all these sorts of extreme cases are often carried out by people who have experienced a lot of social rejection".

The latest study on rejection, reported in the journal Science, used a computer game called Cyberball that Williams and his students made. In it two figures throw a ball to each other and to the human player.

The brains of 13 young people were monitored by functional magnetic resonance imaging as they played three rounds of the game. They were told the computer figures represented real people playing elsewhere.

In the first round they were told they could not join in the game because of technical problems. In the second round they all played happily. Soon after the third round began, the computer figures stopped throwing the ball to the real player.

The brain scans revealed that there was heightened activity in a region called the anterior cingulate, which is associated with physical pain, in the first and the third round.

Even though the players knew they had not been actively snubbed in the first round, the rejection still registered automatically in the brain, says Lieberman.

The more distressed the players felt about being excluded in the third round, the more active their pain region was.

In the third round, elevated levels of activity were also detected in another area called the right ventral prefrontal cortex, which is associated with thinking about emotions and self-control. The more active this region, the less active the pain region, which suggests it helps people cope better with getting the cold shoulder.

Social ostracism deprives people of four basic needs: a sense of belonging, control, self-esteem and meaningful existence. But Williams's research has also shown it can lead not just to antisocial behaviour, but also to "pro-social" behaviour, where shunned people work harder to try to please their social group.

Commenting on the latest study, Professor Jaak Panksepp of Northwestern University in Illinois, says brain scans could also throw light on the nature of love.

"A reasonable working hypothesis is that social feelings such as love are constructed partly from brain neural circuits that alleviate the feelings of social isolation," he says.