Women sniff out ambition in a sexual partner while men eye up good looks

The secret of sexual attraction lies in the movement of a woman's eyebrow and the natural smell of a man, two studies on human mating behaviour presented to the American Psychological Society's annual conference reported yesterday.

Men say that a woman's looks are the most important factor behind sex appeal and regard a raised eyebrow as a strong indication of interest. Women are more impressed by a man's odour and say a healthy streak of ambition is a big factor behind desire.

Professor Rachel Herz, of Brown University, New York, used a group of 231 heterosexual college students to compare what men and women look for when selecting a mate.

The students were asked to assess the importance of various physical and social characteristics using a numerical scale.

Female students singled out body odour from all other sensory experiences as the most likely to affect desire, while men were relatively neutral on a lover's natural scent.

Body smell is linked to a person's immunological make-up and Professor Herz said women sniffed out mates with different antibodies so they had the greatest chance of healthy offspring.

Both sexes said a good personality was the single biggest factor in choosing a mate. But male students ranked physical attractiveness and appearance much more highly than did their female counterparts.

Professor Herz: "Both sexes valued pleasant disposition as the most important criterion for mate choice.

"However, women valued smell and ambition more highly than did men, while men valued looks more highly than women." The second study by Professor Adam Brown showed that men regard women with low eyebrows as the least attractive.

He tested the theory that women will raise their eyebrows if they meet a man the find attractive, giving him a sign that she is interested.

College students were given sets of three photos of women and asked to rank them in terms of attractiveness.

Professor Brown of St Bonaventure University in New York said women with higher eyebrows, which was seen as a welcoming feature, were generally rated as the most attractive.