Many of us want to make wise, rational, strategic choices and yet we are swayed this way and that by mysterious currents running beneath the surface of consciousness. Shedding some light on these invisible forces is a new study showing that when it comes to risk, other people tend to push us in the direction we’re already trending.
That is, when given information about the choices of other people, risk-takers tended to take even greater chances, while the risk-averse became more careful. Exploring this phenomenon further, the researchers used brain scanning to discover that when they exposed subjects to choices of like-minded people, they saw greater activity in part of the brain associated with value than when they exposed the same subjects to the choices of people on the opposite side of the risk-taking spectrum.
People generally tend to change their preferences when they’re exposed to information about the choices other people made, said the study’s lead author, Pearl Chiu of Virginia Tech. She referred to the human tendency to imitate one another as herding. “But we don’t know why, especially around risky decisions,” she said. “We wanted to study the brain mechanisms behind how social factors influence our decisions.”
Understanding these patterns may be useful in helping people avoid reckless behavior, such as drug abuse or risky sex, said Chiu. And the result could give us all insight into the way we intuitively make decisions that involve elements of risk. The findings were published in this week’s issue of the journal Nature Neuroscience.
Chiu said they assessed risk-taking tendencies by giving 70 subjects different types of lotteries – they could have a sure payoff of $5, or 50/50 odds of getting either $10 or nothing, for example. In this case they went with a lottery that offered a 70% chance of getting a modest payout and a 30% chance getting a higher one. That allowed them to assess how prone the subjects were to taking risks – their “individual risk preferences.”
Then the researchers tested people in groups of three to see whether their behavior changed when they saw the decisions other people made given the same set of options. That’s when they found people were more prone to imitate others who were on their own side of the spectrum – that is, they were nudged further in the direction of their original tendencies. “If you’re a risk-averse person you’re more likely to be influenced by seeing someone make a safe choice than if you see someone make a risky choice and if you’re a risk-seeking person you’re more likely to be influence by people like you,” she said.
Then, she and colleagues put the subjects into a brain scanning machine – a functional MRI – to get a better picture of what was making them act this way. They found that information on the choices of other subjects cased activity in a region called the ventromedial prefrontal cortex, which the researchers say encodes our sense of value. “The more it was activated the more it predicted whether you were going to follow other people’s decisions,” she said. The region was activated much more when subjects were exposed to the choices of other people who were on their side of the risk spectrum – suggesting they valued the information about choices of those who were similar much more than the information about those who were different.
The findings might be useful not just for self-understanding but for figuring out how to influence people and which people to try to influence. It turns out people are more malleable in some directions than others.
