It seems you can judge a book by its cover. Psychologists have found that antisocial and irresponsible individuals are identifiable just from their photographs.
Their findings suggest that the face can betray many of humankind's worst character traits, even in a still image. The work echoes the ideas behind the discredited theories of phrenology and physiognomy, in which the bumps of the skull or shape of the face were linked to personality characteristics.
Mark Shevlin, lecturer in psychology at the University of Ulster at Magee College, said: "The findings, to some degree, support the belief that people can judge another person's character just by looking at them."
The research was carried out at the University of Ulster's School of Psychology at Magee College and involved 62 participants who were divided into "targets" and "judges". The targets were then assessed by filling in a questionnaire. This used a system to summarise personality in three cross-cultural super traits: extraversion (sociability, activity and assertiveness), neuroticism (anxiety, inferiority and unhappiness) and psychoticism (risk-taking, impulsiveness and irresponsibility).
Each target was asked to maintain a neutral facial expression when their picture was taken. The photographs were then randomly displayed on a computer screen and each judge was asked to rate them in terms of extraversion, neuroticism, psychoticism, attractiveness and babyfacedness.
The psychologists found that targets and judges consistently agreed on psychoticism. No other trait produced statistically significant results.
This was the case even when the judges were shown closely cropped photographs that restricted the image to just the target's face.
Hans Eysenck, the leading British psychologist who devised the personality trait system used in the experiment, sparked controversy when he suggested that psychoticism predicted criminality, aggression, drug abuse and even schizophrenia.
Dr Shevlin suggested that the ability to pick up on psychoticism might have been acquired through natural selection. He thought it might help women avoid men whose personalities were ill suited to long-term commitment and child-rearing.
The research, which was carried out by Dr Shevlin and four colleagues at Ulster and Nottingham Trent universities, builds on previous studies that have indicated that the face contains clues to character traits. It will be published in the journal Personality and Individual Differences next month.