But not only are blondes just as smart as women with other hair colors, according to a new study, labeling them as "dumb blondes" can have negative effects on their careers.

Researchers at The Ohio State University studied 10,878 Americans—men and women—who answered a series of questions from the U.S. Bureau of Labor Statistics meant to determine their intelligence over almost a decade. The study concluded that white women with natural blonde hair had an average IQ within three points of women with other color hair—brunettes, redheads, and women with black hair included. In fact, the average IQ of blondes was slightly higher than those with other hair color.
The "dumb blonde" stereotype persists, however—and apparently it has some serious consequences. "Research shows that stereotypes often have an impact on hiring, promotions, and other social experiences," said Jay Zagorsky, author of the study and a research scientist at The Ohio State University. "This study provides compelling evidence that there shouldn't be any discrimination against blondes based on their intelligence."

The study couldn't posit whether there are genetic reasons hair color and intelligence could be correlated, but the researchers have one hint at why blondes might have slightly higher intelligence: They often grow up in homes with more reading material than women with any other hair color.

"If blondes have any slight advantage, it may simply be that they were more likely to grow up in homes with more intellectual stimulation," said Zagorsky.

So the next time you're tempted to equate being blonde with a lack of smarts, think again: They're not just as smart (or smarter!) than the next gal, they're also just as deserving of that job or promotion.