PSYC Research Shows Brain Function behind Social Norms

Around the world and throughout history, humans have created and followed social norms. They regulate what is forbidden, what is expected, and what is rewarded. They also vary widely across cultures. But despite the profound importance of social norms, scientists have yet to discover how they are processed in the brain. New research by Professor of Psychology Michele Gelfand and her colleagues represents a major step toward resolving norms’ neural basis.

Gelfand and Yan Mu, a post doctoral researcher who co-led the project, recruited 25 participants from China and 25 participants from the United States to participate in an electroencephalography (EEG) study. The researchers chose these two countries because previous research had found China to have much stronger norms than the United States, and less tolerance for deviant behavior. Gelfand had termed this difference in norm strength “tightness-looseness,” in a previous paper in Science and identified China as a tight country and the United States as a loose country, generally speaking.

The new study, “How culture gets embrained: Cultural differences in event-related potentials of social norm violations,” appears in Proceedings of the National Academy of Sciences.

“We’ve made some headway toward answering questions such as, ‘When somebody crosses the road at a red light or sings in the library, how does our brain respond? Will people from different cultures have similar or different responses in their brains,’” Gelfand said.

In the study, Chinese and American subjects were connected to an EEG apparatus that monitored their neural activity over time and read sentences that portrayed people either following norms or deviating from them. For example, a participant might read about “Sally”, who was “dancing in the art museum” (norm violation) or “Sally” who was “dancing in a tango lesson” (norm following).

When the researchers analyzed the data, they found a reliable brain signal that emerged 400 milliseconds after participants saw a norm violation. This signal is called the “N400,” and appears to be stronger in the central and parietal regions of our brains for both Chinese and U.S. participants when we witness someone violating a norm.

The N400 signal in the frontal and temporal regions was significantly stronger amongst Chinese participants but not amongst Americans, suggesting that the tightness of one’s culture influences how one’s brain responds to norm violations. Furthermore, participants who reacted more strongly to norm violations felt a greater sense of cultural superiority, had more self-control, but were less creative—in keeping with previously established traits of cultural tightness.

Gelfand said that experiment provides unique insight into both the neural basis of social norms and the development of Chinese and American culture.

“It illustrates, for the first time, how the brain detects social norm violations, and helps us understand how the brain supports and reinforces cultural differences across tight and loose cultures,” said Yan Mu

The paper was also coauthored with Shinobu Kitayama of the University of Michigan, and Shihui Han of Peking University.

Published on Mon, Nov 30, 2015 - 2:52PM