MRI scans revealed higher activity in the brain's striatum, linked to rewards, when a gambler beat a friend in the lottery vs. when the gambler won alone (the medial prefrontal cortex, linked to social reasoning, showed similar patterns). Victorious group gamblers were also more likely to behave riskier in subsequent lottery trials. In other words, our brain values winning amongst others more than winning alone.
Researchers see an evolutionary correlation as strong incentives exist for high social rank, as dominant animals gain privileged access to limited resources and being alone induces risk-aversion because one bad gamble can be fatal especially without a social network.
