Scientists revealed the neural signals that cause trends to spread among groups of people, and how people influence the decisions of others.
Brain scans showed participants increased their perceived value of a gamble when they saw other people take it, Virginia Tech reported. The observed neural signals were also able to predict how likely a participant was to conform to the choices of others.
"You're more likely to follow the risky decisions of other people if you like to take risks, and you're more likely to follow the cautious decisions of other people if you tend to be cautious," said Pearl Chiu, senior author on the paper and an assistant professor at the Virginia Tech Carilion Research Institute. "Our data explain why this happens. The choices that others make become more valuable than they would be otherwise, and our brains are wired to choose things that are more valuable."
In the study, the researchers offered the choice between a guaranteed win of $5 or a 50 percent chance of winning $10 on each turn. The researchers observed both safe and risky behavior among the participants, even though they ended up with the same amount of money on average. The safe and risky choices of the participants also proved to have an influence on the choices of others.
"Our preferences about risks extend to the type of peers who are more likely to influence our choices," said Brooks King-Casas, coauthor on the paper and an assistant professor at the Virginia Tech Carilion Research Institute. "This goes beyond negative peer pressure and demonstrates why strong social support systems are effective for encouraging healthy choices."
The scans focused on a region of the brain called the ventromedial prefrontal cortex, and found this is where the social valuation process occurs. This region has also been linked to the processing of values and rewards. The researchers believe the likelihood of someone being influenced by the behavior of others is linked to how much they value what that person says. Individuals filter what information they consider during the decision-making process in their own way.
"The brain starts with your own preferences as a baseline for what to choose, and then, on top of that, the more your brain values information from other people, the more likely you are to follow their choices," said Chiu, who is also an assistant professor in Virginia Tech's Department of Psychology. "At the same time, if the other choices are too different from what you tend to do, your brain also detects that, and may be partly why the same social force is enough to budge some people but not others."
The findings were published in a recent edition of the journal Nature Neuroscience.
