Proof at last: gentlemen do prefer blondes

Largest ever genetic study uncovers evolutionary evidence that fair-haired women are more attractive

IT WAS Heidi Klum, the model, who perhaps most pithily summed up the experience of being blonde when she compared it to “buying yourself a lightbulb”.

That may once have been written off as nothing more than lazy cliché, but, according to evolutionary science, she was absolutely right: gentlemen really do prefer blondes.

Researchers conducting the largest ever genetic investigation into hair colour have discovered that, among people of European descent, women are 20per cent more likely to have blonde hair than men.

It means that, as mankind evolved, blonde women have been disproportionately more successful at passing on their genes.

A team at King’s College London set out to discover why. Using their discovery of more than 100 new genes known to play a major role in determining human hair colour, they attempted to identify any connections between the “blonde genes” and those known to influence good or poor health.

They also sought to establish any links between a genetic propensity for blondeness and femininity itself in the X chromosome.

None, however, was found.

It has led them to conclude that throughout human history blonde women have enjoyed a “mating preference”. In other words, men have been more likely to want to procreate with them simply because of how they look.

Published in the journal Nature Genetics, the study marks a breakthrough in the understanding of hair colour.

Although previous studies have found that a large percentage – around 97per cent – of hair colour variation is explained by heritable factors, only 12 hair colour genes had been identified up to now. In order to identify the previously unknown hair colour genes, researchers analysed DNA data from almost 300,000 people of European descent, together with their self-reported hair colour information from sources including the UK Biobank.

“Our work helps us to understand what causes human diversity in appearance by showing how genes involved in pigmentation subtly adapted to external environments and even social interactions during our evolution,” said Prof Tim Spector, who took part in the research.

“We found that women have significantly fairer hair than men, which reflects how important cultural practices

‘Our work shows how genes involved in pigmentation subtly adapted to … social interactions’

and sexual preferences are in shaping our genes and biology.”

The team has said it believes the discovery of the new genes will significantly improve the ability of forensic investigators to track down criminals using DNA.

It also promises new insights into conditions related to skin pigmentation, such as skin, testicular, prostate and ovarian cancers

“While the genetics of hair colour is an interesting problem in itself, we hope that better understanding of the biology of melanin pigmentation will be applicable to studies of diseases that interact with pigmentation, such as skin cancer or vitiligo,” said Dr David Hinds, who co-authored the paper.

The King’s College London team is not the first to investigate whether blonde women are more likely to have children. In 2008, newly examined letters by Charles Darwin revealed he had devoted a significant amount of time to examining whether hair colour affected a woman’s ability to find a mate.

The naturalist went as far as trying to obtain records from Bristol Royal Infirmary indicating the hair colour of its married and single patients.