A close-up of an eye showing the reflection of a person holding a camera in the center of the pupil. Image credit: Gaurav Chandawale (CC BY 2.0)
People, especially adolescents, often act differently around their peers than around their parents, and tend to take more risks when they are with peers. People usually copy the behavior of others and make similar choices. But previous research suggests that humans are also likely to take more risks when others observe them. Scientists think that making decisions could be influenced by what people think they know or believe about other people’s preferences.
Seon and Chung tested the hypothesis that people are influenced by both the choices of peers and by their beliefs about the preferences of those around them. To examine this, they designed an experiment in which participants made decisions while being observed by one of two different partners. Before the experiment began, participants had the chance to observe each partner’s decisions and thereby learn that one tended to take risks while the other preferred to play it safe. By analyzing both their choices and their brain scan data, they investigated whether people adjusted their decisions depending on the observing partners' preferences.
Before learning about the preferences of others, participants thought that anonymous observers would choose riskier options than they themselves would. Through repeated observation, however, they discovered which partner tended to take more risks and which tended to play it safe. This led participants to adjust their own choices depending on which partner was watching.
Computational modeling showed that people were not simply copying the observer’s behavior. Instead, they mentally simulated what the partner would have done in the same situation, based on what they had learned, and let these predictions guide their decisions. Brain scans revealed that two brain regions involved in social cognition – and the strength of the connection between these regions – explained individual differences in how much people relied on these predictions when making choices.
These regions, the temporoparietal junction and dorsomedial prefrontal cortex, are often referred to as the social brain and are thought to play a key role in the mental simulation of other people’s intentions. People who relied more on their own predictions about observers showed greater sensitivity in these regions. The connection between the regions increased or decreased depending on whether a partner was observing.
This study suggests that our choices are shaped by what we think an observer would do. These insights help explain everyday behaviors, such as why people post differently on social media when they expect certain reactions, or why opinions change in group settings. Such knowledge can shed light on social pressure and online influence. Still, because real-life situations are much more complex, further research in natural social environments is needed.
