They give Action Man a certain ruggedness and bestow instant testosterone on movie heroes, and according to British psychologists, facial scars can also make men more attractive to the opposite sex.

Men with mild facial scars were typically ranked as more appealing by women who were looking for a brief relationship, though they were not considered better as marriage material, a study found.

In the same experiments, women with facial scars were judged to be as attractive as those without, the researchers said.

The sexual allure of the facial scar has long puzzled psychologists. Many believe they are seen by women as a sign of masculinity and an exciting, risk-taking personality, though in Shakespeare's All's Well that Ends Well, an old lord, Lafeu, takes a different slant, commenting: "A scar nobly got, or a noble scar, is a good livery of honour."

Psychologists at the universities of Liverpool and Stirling decided to investigate the effects of facial scars by asking 115 women and 64 men to rate the attractiveness of eight strangers of the opposite sex. Half were asked to look at original face shots, while the other half viewed images that had been digitally manipulated to add scars to their cheeks, jawbones or foreheads.

While the scars made no difference to the perceived attractiveness of women, scarred men ranked 5.7 percentage points higher in the appeal ratings than those with undamaged skin.

"A large scar is unlikely to make you more attractive, but there are some scars that women do seem to find appealing. There's the whole James Bond thing, where a person is attractive but probably not the best marriage material," said Robert Burriss, a psychologist at Liverpool who led the study.

For each picture, volunteers were asked to guess whether the scar was from a fight, an accident or illness. The men's scars were often blamed on a violent encounter, while those on women were often attributed to accidents.

"When scarring is seen as the result of a violent encounter, it signifies strength or bravery in a guy, or it could be due to an accident, and so evidence of a risk-taking personality. Either way, it's another way of assessing a man's masculinity," Burriss said. Men without scars could be seen as more caring and cautious, and so more suitable for a long term relationship, he added.

The study appears in the journal Personality and Individual Differences.