London: Social pressures that come from meetings or group settings cause a drop in individual intelligence levels, a new study has revealed.

Working in a group makes people perform worse on intelligence tests, as some group members are so anxious about doing well that they 'divert' their brain power towards maintaining their social status in the group.

"You may joke about how committee meetings make you feel brain dead, but our findings suggest that they may make you act brain dead as well," a daily quoted Read Montague, study leader at Virginia Tech, as saying.

Groups of volunteers showed measurable drops in IQ when asked to perform intelligence tests socially, with the results broadcast to the group.

Some people performed well in the 'social' tests, but others were affected badly - and overall, performance dropped.

Women appear to feel this pressure more than men - only three out of 13 female volunteers performed well in a social environment, with 10 out of 13 finding that their performance dropped.

The researchers used a magnetic resonance imaging (MRI) scanner to monitor how people's brains responded - and found that bad performers tended to show activity in parts of their brain that dealt with emotions and anxiety.

'Even subtle social signals may have a dramatic effect. By placing an emphasis on competition, are we missing a large segment of the talent pool?' said Virginia Tech's Kenneth Kishida, who is the lead author of the study.

"Our study highlights the unexpected and dramatic consequences even subtle social signals in group settings may have on the individual," said Kishida.