This is not a joke, but after all the blonde jokes on here, I thought that this might be the appropriete place for it.

Encounters with blonde women such as U.S. film icon Marilyn Monroe make men's mental performance decline, a study has found.

University of Paris X-Nanterre professor Thierry Meyer said the study he co-authored found that when men are around blonde women, their mental performance declines due to prevailing social stereotypes, The Sunday Times of London reported.

The social psychology professor said study subjects were given general knowledge tests after being exposed to a variety of women, and seemed unconsciously to begin to "think blonde."

"This proves that people confronted with stereotypes generally behave in line with them," Meyer said. "In this case blondes have the potential to make people act in a dumber way, because they mimic the unconscious stereotype of the dumb blonde."

Although the finding appeared to reinforce the influence of stereotypes on behaviors and abilities, "EastEnders" and "Doctor Who" star Michelle Collins had a different take.

"I don't think it's to do with hair at all; it's all about the breasts," the blonde actress told the newspaper.