THE secrets of sexual attractiveness are to be explored by researchers at a scientific event next month.

Scientists from Newcastle University, who are studying the underlying genetic mechanisms that determine attraction, have been invited to take part in the Royal Society Summer Science Exhibition.

The researchers believe humans instinctively scan a potential mate's face for signs of "good" genes.

To test this hypothesis, the team will invite some of the anticipated 3,000 visitors to the show to take part in a "Mate Choice" experiment.

Dr Marion Petrie, a member of the biology department at Newcastle University, said visitors would be asked to look at photographs of human faces, in black-and-white and then in colour, and grade them in order of attractiveness.

They are especially interested in the relative appeal of different skin textures and colours.

"One of our more recent findings is that you can tell something about someone's underlying genetic quality from the face alone," she said.

"We all know faces are attractive but we don't really know why," said Dr Petrie, who is part of a group of researchers looking at a new area of science called neuro ecology or neuroinformatics.

"We have discovered that either skin colour or texture is important in determining attractiveness, with a big sample of people we will try to do a couple of experiments to pin that down," she said.

"As part of our research we have genotyped people so we are linking all sorts of things that people find attractive to specific, identifiable genes.

"Eventually, we hope to understand the underlying mechanisms of human mating."

The exhibition takes place at the Royal Society, in London, from July 1 to July 3. For further information visit www.royalsoc.ac.uk