Women with high IQs are far more likely to take cannabis, cocaine and ecstasy in their thirties, a study has found.
Researchers think they are more open to new experiences so are more willing to experiment with illegal substances.
The study by Dr James White from Cardiff University found that women with higher than average IQ scores were twice as likely to have taken drugs such as cannabis, cocaine, ecstasy and amphetamines in their thirties as those with lower scores.
Dr White looked at the records of 8,000 people dating back to the 1970s who had all had their IQ measured at the ages of five and ten.
They had also answered questions about whether they had taken any drugs when they were 16 and again when they were 30.
The study, published in the Journal of Epidemiology and Community Health, found that women aged 30 who had higher than average IQs – between 107 and 150 - were more than twice as likely to have used illegal substances compared to those with scores of less than 95.
An average IQ score is 100.
Men with high IQ scores were 50 per cent more likely to have used amphetamines, ecstasy, and several illicit drugs than those with low scores – so the link was not as strong as amongst women。
Dr White said: "If we were to speculate it could be that people with high IQs tend to be more open to new experiences."
"They also don't think they are at risk by just trying once or twice."