Faces that are deemed to be untrustworthy, dominant or unattractive by their shape can be made to appear the opposite by certain facial expressions, according to scientists in the UK.
They say this "social camouflage" can be practiced and deployed by people to mask the default social impression inferred from their face and ingratiate themselves to others in a host of situations.
"Humans communicate a lot through their facial expressions when negotiating various social situations," said Doctor Daniel Gill, Research Associate at the Institute of Neuroscience and Psychology at the University of Glasgow.
"But whether we like it or not, previous well-documented research has shown that people tend to perceive certain personality characteristics or traits in individuals based on the structure of their face," Gill said.
"This means some people can be judged to be untrustworthy or domineering simply by how they look – a square jaw and large brow conveying dominance, for example it can have implications for things like mate selection and job opportunities," he said.
"However, there are also basic facial movements that people identify with specific social traits and these movements can override the default impression people have of another person's face," Gill said
"The researchers used software to generate three-dimensional animated images of faces which can be programmed to move one or more of 42 individual facial groups of muscles – or action units, as they call them – to form a facial expression.
They then asked a group of 12 volunteer observers to judge a set of randomly generated facial expressions on trustworthiness, dominance and attractiveness.
This allowed the researchers to ascertain what aspects of an expression conveyed these particular characteristics.
They repeated this procedure again with a different set of volunteers, this time asking them to rate static faces with neutral expressions for the same traits, but based solely on facial morphology – or structure.
Finally, to test whether the static, neutral faces deemed to be untrustworthy, dominant or unattractive could be made to appear trustworthy, submissive and attractive, the researchers animated the second set of faces with the expressions identified with these characteristics from the first experiment.