People are pretty good at judging whether a crowd is friendly, but anxious people may be worse at this task, a new study finds.
The research, which was presented Monday at a meeting of the Society for Neuroscience, could point toward a better way to diagnose anxiety and other mental-health problems.
In the study, scientists morphed the faces of three men and three women to look either extremely happy, extremely angry, or somewhere in between. Then they showed male and female volunteers "crowds" of four to six faces to each eye independently and asked the participants to press a key to indicate which group felt more approachable. Each crowd of faces contained a range of emotions.
The scientists found that overall, people more accurately identified happy female crowds and angry male crowds, while they had a harder time accurately identifying angry female crowds and happy male ones. But it made no difference whether it was a man or woman viewing the faces.
The study participants also filled out a questionnaire about their anxiety level (which is also used to diagnose anxiety clinically). On the basis of their responses, they were divided into a high-anxiety and a low-anxiety group.
Compared with those in the low-anxiety group, people in the high-anxiety group tended to make more mistakes in identifying happy crowds and were less likely to find happy crowds approachable. But the high-anxiety individuals were better at recognizing angry crowds - suggesting they may be more vigilant in negative or threatening situations.
Anxiety may be linked to an overly sensitive amygdala, a brain region responsible for processing emotion, study leader Hee Yeon Im, a psychologist at Harvard Medical School, told Business Insider. Anxious people are very nervous, and they may be more attuned to potential social threats, she added.
The researchers also tracked people's eye movements when looking at the crowds and found that their eyes were first drawn to whichever face showed the most extreme emotion (happy or angry). This suggests the brain prioritizes extreme emotions when evaluating a crowd, the researchers said.
Im and her colleagues are working on studying what is going on in the brain during this crowd-emotion task. By connecting the brain mechanisms to the behavior, the researchers hope to improve the clinical diagnosis of anxiety.