Washington: Blondes have long been the butt of jokes for their supposed lack of intelligence.But those with a fair head of hair can now take heart - for scientists have disproved the dumb blonde stereotype.
The study of 10,878 Americans found that white women who said their natural hair colour was blonde had an average intelligence quotient (IQ) score within 3 points of brunettes and those with red or black hair.
"Research shows that stereotypes often have an impact on hiring, promotions and other social experiences," said Jay Zagorsky from Ohio State University.
"This study provides compelling evidence that there should not be any discrimination against blondes based on their intelligence," said Zagorsky.
The study found that the average IQ of blondes was actually slightly higher than those with other hair colours, but that finding is not statistically significant, he said.
"I do not think you can say with certainty that blondes are smarter than others, but you can definitely say they are not any dumber," he added.
The results for blonde white men were similar - they also had IQs roughly equal to men with other hair colours.
Data from the study came from the US National Longitudinal Survey of Youth 1979 (NLSY79), a national survey of people who were between 14 and 21 years old when they were first interviewed in 1979.
The findings showed that blonde-haired white women had an average IQ of 103.2, compared to 102.7 for those with brown hair, 101.2 for those with red hair and 100.5 for those with black hair, Zagorsky said.
Blonde women were slightly more likely to be in the highest IQ category than those with other hair colours, and slightly less likely to be in the lowest IQ category, he said.
The findings were published in the journal Economics Bulletin.