A new brain study suggests that peer pressure could be hardwired in our brains, possibly explaining why we do more daredevil things when our friends are around than when we are on our own. Participants who won a game in a social setting showed more activity in the social reasoning part of their brain than when on their own, and they were also more likely to engage in riskier decisions.
The study was the work of an international research team led by Georgio Coricelli of the University of Southern California Dornsife College of Letters, Arts and Sciences, who write about their work in the 6 September issue of the online journal Proceedings of the National Academy of Sciences, PNAS.
For the study they used functional MRI (fMRI) to measure brain activity while participants chose between two lotteries: one played privately, and one played socially against others. The participants saw what the result of the unchosen lottery was in the private situation and they also saw what the other person chose in the social situation (ie they could see whether they won or lost in both cases).
The results suggest that the brain puts more value on winning in the social setting than in the solitary setting.
When participants beat a colleague in the lottery, their striatum, the part of the brain that is linked to reward, appeared more active on the fMRI scan than when they won on their own.
Their medial prefrontal cortex, the part of the brain that is linked to social reasoning, also showed more activity in the social than in the solitary situation, and the participants who won when they played against others also tended to make riskier choices in subsequent lotteries.
The researchers write:
“Specifically, striatal activity associated with social gains predicted medial prefrontal cortex activity during social choices, and experienced social gains induced more risky and competitive behavior in later trials.”
Coricelli, who specializes in the study of human behaviors that emerge from the interplay of cognitive and emotional systems, told the press that these findings:
“… suggest that the brain is equipped with the ability to detect and encode social signals, make social signals salient, and then, use these signals to optimize future behavior.”
He explained that when we are on our own, losing can be more life-threatening: there is no social support network to fall back on if our risky choice does not pay off.
But when we are in a group, rewards tend to be of the “winner takes all” kind, and this is especially apparent in sexual competition, where, Coricelli said, borrowing a phrase from American racing car legend Dale Earnhardt, Sr, “second place is just first loser”.
Animals have strong incentives to be at the top of their social group.
“Animals in the dominant position use their status to secure privileged access to resources, such as food and mates,” said Coricelli.
Written by Catharine Paddock PhD