By Karen Hebert Bristol

A man's sex appeal may lie in his cheeks, or so evolutionary biology researchers at the University of Newcastle claim. They have found a link between a man's cheeks and a woman's perception of his attractiveness.

Professor Marion Petrie, chair of the team, said that the study presented at the Royal Society's Summer Science Exhibition 2003 was aimed to answer the question, "Why are women choosy?"

The findings were based on a study of 90 women, who were asked to study 76 men's faces and then rank them in order of attractiveness.

The women were then shown only a small square of each man's face and again were asked to rank these in order of attractiveness. The rankings matched for both tests.

DNA tests looking at particular genes involving the immune system were also carried out on the men, and those with what the researchers described as "good genes" were deemed to be most attractive.

The study found that women were subconsciously selecting healthy men with genes that were different to their own and so would give potential offspring a diverse mix of genes, a strong immune repertoire and would also avoid the possibility of inbreeding.

"Their assessments of healthiness and attractiveness were related to the genetic composition of these men," Professor Gosling, one of the researchers, told BBC News Online.

"Perhaps women choose healthy men because they believe they will live longer and will be there to help them to raise children. They may also see these men as being more resistant to diseases and less likely to pass on illness to their offspring," he added.