MEETINGS make people stupid because they impair their ability to think for themselves, scientists have found.
The performance of people in IQ tests after meetings is significantly lower than if they are left on their own, with women more likely to perform worse than men.
Researchers at the Virginia Tech Crilion Research institute in the US said people's performance dropped when they were judged against their peers.
Read Montague, who led the study, said: "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.
"We started with individuals who were matched for their IQ. Yet when we placed them in small groups, ranked their performance on cognitive tasks against their peers, and broadcast those rankings to them, we saw dramatic drops in the ability of some study subjects to solve problems. The social feedback had a significant effect."
Students from two universities with an average IQ of 126 were subsequently pitted against each other, and told how they were performing in comparison to the others after answering each question.
Researchers found that most people performed worse when they were ranked against their peers, suggesting the social situation itself affected how well they completed the IQ tests.
Women were affected by the situation more clearly than men.
Three out of 13 women remained in the high-performing group while ten out of 13 fell into the low performing group.
Subsequent MRI scans showed different areas of the brain associated with problem solving, emotion, and reward were activated when carrying out the tasks.
Lead author Kenneth Kishida, a research scientist at the Virginia Tech Carilion Research Institute said: "Our study highlights the unexpected and dramatic consequences even subtle social signals in group settings may have on individual cognitive functioning.
"And, through neuroimaging, we were able to document the very strong neural responses that those social cues can elicit.
"We don't know how much these effects are present in real-world settings.
"But given the potentially harmful effects of social-status assignments and the correlation with specific neural signals, future research should be devoted to what, exactly, society is selecting for in competitive learning and workplace environments.
"Understanding how our brains respond to dynamic social interactions is an important area of future research. We need to remember that social dynamics affect not just educational and workplace environments, but also national and international policy-making bodies, such as the US Congress and the United Nations."
The study raises questions over how intelligence is measured and whether it is fixed, experts said.
Co-author Steven Quartz, professor of philosophy in the Social Cognitive Neuroscience Laboratory, said: "This study tells us the idea that IQ is something we can reliably measure in isolation without considering how it interacts with social context is essentially flawed.