Blondes have more fun but men prefer brunettes according to a University of Westminster study

(EndPlay Staff Reports) - There's good reason why some celebrities have dyed their hair from blonde to brunette – men seem to prefer darker-haired women.

That's according to researchers in England, who sent a woman to three London nightclubs. For each trip her hair color was dyed brunette, blonde and then red. The researchers from the University of Westminster then observed how men approached her, reported The Daily Mail .

The researchers, who returned to the clubs, asked 130 men to rate pictures of the woman in her three hair colors. Her brunette guise generated the highest marks for attractiveness and intelligence, reported the Scandinavian Journal of Psychology.

Preferences could simply be the result of a shift in fashion, according to researcher Viren Swami. While blondes were the rage in the '70s and '80s, brunettes seem to have regained their favor today.

"In the sixties and early seventies, when Jackie Kennedy was the ideal, brunette hair became the ideal for women generally," Swami said. "Then, in the seventies and eighties, blondes became the ideal.

The study did find that men spoke most often to the blonde version, chatting with her 60 times in total, compared to 42 approaches as a brunette and 18 as a red-head.