Back in the ice age, Northern European cavemen got all the chicks.
Thanks to a food shortage and a man shortage about 10,000 years ago, men were in such demand they had their pick of mates.
With so much competition among women to find a mate, nature and evolution kicked in to give some cave women a distinctive look to attract the opposite sex: blond hair and blue eyes.
So says a new study published in the British science journal Evolution and Human Behavior.
Are Blondes Mutants?
The study's author, Canadian anthropologist Peter Frost, concludes that although blond hair and blue eyes started as a genetic mutation, men were pulled in by the golden locks and baby blues, thus populating the area with blond and blue-eyed children.
While the rest of the world has predominantly brown hair and brown eyes, Northern Europeans have the greatest variety of hair and eye color found anywhere, and Frost believes it resulted from the sexual appeal of these traits.
"When an individual is faced with potential mates of equal value, it will tend to select the one that 'stands out from the crowd,' the study said.
Still, the study admits it's unclear why the mutation happened in Europe and not elsewhere.
The theory is backed by several other studies, including one conducted in Japan that found that the gene responsible for blond hair appeared for the first time about 11,000 years ago.
The Grass Is Always Greener
Though a caveman bachelor may have had no problem finding a date for Saturday night, his existence was far from ideal.
According to the study, men of the time were forced to go on long hunting expeditions over vast areas to find their prey.
With no means to preserve food for the journey, an unforgiving ecosystem and the risks presented by the hunt itself, some men never made it back.
The ones who did were highly sought after.
To add to the difficulties, women weren't really equipped to gather food and the arctic environment didn't allow for opportunities close to home. Frost argues that if a woman wanted to eat, she needed a man.
Women had to attract men to survive.
Frost concluded that Mother Nature answered the call by introducing hair and eye colors -- like the more than seven distinct colors found in Northern and eastern Europe today.
If he is correct, it appears that even 10,000 years ago, blondes had more fun.