The Telegraph, June 17, 2008
Scientists may have discovered the reason why some people always look glum.
Limited or very specific facial expressions could be explained by the fact that some humans have fewer muscles in their face than others, research from the University of Portsmouth suggests.
The findings could perhaps explain why certain people, such as the character Victor Meldrew in the television series One Foot in The Grave, seem to have a permanent scowl.
The study, published in the American Psychological Association Journal, found that all human being have the same set of five “core” facial muscles.
Dr Bridget Waller, who led the research, believes that these muscles control our ability to produce standard expressions showing anger, happiness, surprise, fear, sadness and disgust.
But there are an extra 14 muscles which can be present in the face, and many people do not have a full set.
Dr Waller, from the university’s Centre for the Study of Emotion in the Department of Psychology, said: “Everyone communicates using a set of common signals and so we would expect to find that the muscles do not vary among individuals. “The results are surprising – in some individuals we found only 60 per cent of the available muscles.”
One muscle, used to control our ability to create an expression of extreme fear, is found in only two thirds of the population, the study shows.
Dr Waller, from the university’s Centre for the Study of Emotion in the Department of Psychology, added: “Some less common facial expressions may be unique to certain people.
“The ability to produce subtly different variants of facial expressions may allow us to develop individual ‘signatures’ that are specific to certain individuals.”
She said that the only other part of the body where muscles were not uniform was the forearm, where 15 per cent of the population lack a specific muscle.