KEY POINTS:
It may seem obvious to every starry-eyed lover but psychologists have now proved it to be true - if you want someone to find you attractive, look them in the face and smile.
A strong jaw for men, high cheek-bones in women, a perfectly-shaped nose or unblemished
skin may be the physical signs of sexual attractiveness, but it is the gaze of the eyes that really counts.
Psychologists have shown for the first time that you are more likely to find a happy-looking face that looks directly at you sexually attractive than the equally smiling face of someone who is averting their eyes.
The findings support the theory that both men and women use the direction of a person's gaze as a signal of whether that person finds you interesting enough to look you directly in the face - and that sign of interest is, in itself, seen as attractive to the observer.
"It may not seem like a surprising finding. It's exactly as you may expect - that you like people who find you likeable," said Ben Jones, one of the psychologists at Aberdeen University who carried out the study.
But the results indicate something more complex is also going on.
They show that humans are engaging in a game of sexual strategies where both men and women are looking for signs that indicate the level of interest of a potential mate, Dr Jones said.
"They are assessing who is likely to like them. It's not so much about holding eye contact with a member of the opposite sex, it's about looking at someone who you are interested in," he said.
It is all part of an ancient need to concentrate one's limited courting resources on potential mates who are realistically interested in you.
"It wouldn't pay me, for instance, to spend time and effort on chasing supermodels but it would pay me to concentrate on women who smile at me in the street," he explained.
The study, published in the journal Proceedings of the Royal Society B, tested the idea on a group of men and women who were asked to rate the attractiveness of a set of faces of members of the same and the opposite sex.
The pictures showed people smiling, frowning, looking away and looking directly at the observer.
The scientists found that of all the combinations, it was the happy, directly-gazing face that was viewed as the most attractive - especially when the pictures showed a person of the opposite sex to the observer.
This shows both men and women prefer faces of people who seem to like them and that attractiveness is not just about physical beauty.
"It's the first demonstration to show people's preferences for being looked at depends on the emotional state of the person who is doing the looking, as well as their sex," Dr Jones said.
"It makes common sense, but it's the first time it's been shown. What we've shown is that people seem to like someone who likes them - based on the direction of their gaze - and it's particularly true of the opposite sex," he said.
- INDEPENDENT