Detecting lies involves processing social information. How do people process social information and evaluate honesty? And do people process this information differently when it comes from a friend versus a stranger? Yingjie Liu, from North China University of Science and Technology, led a study to explore how people assess different kinds of information from friends or strangers.
As reported in their JNeurosci paper, the researchers used a neuroimaging technique on 66 healthy volunteers as they communicated on computer screens while sitting across from each other. When the information being communicated led to benefits for pairs, this was considered a "gain" and likewise a negative consequence for pairs was deemed a "loss." Says contributing author Rui Huang, "The key reason we chose 'gain' and 'loss' contexts is that they illustrate how people adjust decision-making in response to potential rewards or punishments." Participants believed lies more frequently in "gain" contexts, which was linked to activity in brain regions involved with risk evaluation, reward, and understanding intention. Notably, when the deceiver was considered a friend, the two shared brain activity that varied based on context: "Gain" contexts increased synchrony in a reward-related brain region, while "loss" contexts increased synchrony in a risk evaluation region. The researchers could even use this shared brain activity between friendly pairs to predict whether a person would be successfully deceived.
According to the researchers, this work suggests that people may be more likely to believe lies when they promise the potential of a "gain" and points to brain activity involved in social information processing between friends that may make truth evaluations less accurate.
