Smiling, Frowning Is Hardwired Into Genes: Study

Facial expressions from smiling to sneering are dictated by human genes that all of us share, a new study suggests. Researchers examined the facial expressions on thousands of photographs of blind and sighted athletes at the 2004 Athens Paralympic Games and the 2004 Athens Olympic Games. They discovered that no matter whether athletes could see or not, victors adopted similar wide grins and losers similar frowns or polite, tight-lipped smiles.

The findings cast doubt on theories that facial expressions are learned and may indicate that universal human expressions arose through evolution, scientists say. "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," said one of the researchers, whose work is published in the Journal of Personality and Social Psychology.