Lowered brow, thinned lips, and flared nostrils—we know an angry face when we see one.
“The expression is cross-culturally universal, and even congenitally blind children make this same
face without ever having seen one,” says Aaron Sell, a lecturer at the School of Criminology at Griffith University in Australia and lead author of the study.
The anger expression employs seven distinct muscle groups that contract in a highly stereotyped manner. The researchers wanted to understand why evolution chose those particular muscle contractions to signal the emotional state of anger.
The current research is part of a larger set of studies that examine the evolutionary function of anger.
“Our earlier research showed that anger evolved to motivate effective bargaining behavior during conflicts of interest,” says Sell, formerly a postdoctoral scholar at UC Santa Barbara’s Center for Evolutionary Psychology.