A long-term study that was conducted on about 8,000 people found that those who have high intelligence quotients (IQs) are more likely to use illegal drugs as teenagers and adults than people who have low IQs. The link between IQ and drug usage appeared to be stronger in highly intelligent women, who were more than twice as likely as their peers to have used cocaine and marijuana. Highly intelligent men in the study, which was published in the Journal of Epidemiology and Community Health, were found to be almost 50 percent more likely to have taken amphetamines than lower-IQ men and about 65 percent more likely to have used ecstasy.
More facts about IQ and drug and alcohol usage: