If you think that our facial expressions of emotion are a product of cultural learning, you better think again, for a new study suggests that they are hardwired into our genes.
Published in the Journal of Personality and Social Psychology, this is the first study to suggest that facial expressions of emotion are innate rather than a product of cultural learning.
During the study, sighted as well as blind individuals were found to use the same facial expressions, producing the same facial muscle movements in response to specific emotional stimuli.
Lead researcher David Matsumoto, a professor of Psychology at San Francisco State University, said that the study also provided new insight into how humans manage emotional displays according to social context, suggesting that the ability to regulate emotional expressions is not learnt through observation.
He revealed that the research team compared the facial expressions of sighted and blind judo athletes at the 2004 Summer Olympics and Paralympic Games.
The researcher said that over 4,800 photographs were captured and analysed, including images of athletes from 23 countries.
"The statistical correlation between the facial expressions of sighted and blind individuals was almost perfect. This suggests something genetically resident within us is the source of facial expressions of emotion," Matsumoto said.
He and his colleagues observed that both sighted and blind individuals managed their expressions of emotion in the same way according to social context.
Given the social nature of the Olympic medal ceremonies, according to the researcher, they could form parts of their analyses.
They said that 85 per cent of silver medallists, who lost their medal matches, produced during the ceremony "social smiles" that use only the mouth muscles, compared to true smiles that cause the eyes to twinkle and narrow and the cheeks to rise.
"Losers pushed their lower lip up as if to control the emotion on their face and many produced social smiles. Individuals blind from birth could not have learned to control their emotions in this way through visual learning so there must be another mechanism. It could be that our emotions, and the systems to regulate them, are vestiges of our evolutionary ancestry. It's possible that in response to negative emotions, humans have developed a system that closes the mouth so that they are prevented from yelling, biting or throwing insults," Matsumoto said.