A nine-year study conducted by University College London has found that clever children are more likely to smoke marijuana. The study, published in the journal BMJ Open, found that “high childhood academic at age 11 is associated with a reduced risk of cigarette smoking but an increased risk of drinking alcohol regularly and cannabis use.”

Researchers analyzed data for 6,059 British students and found that students with higher academic scores were twice as likely to smoke pot and drink alcohol regularly, compared to those with lower scores.

“These associations persist into early adulthood, providing evidence against the hypothesis that high academic ability is associated with temporary ‘experimentation’ with substance use.” Researchers believe that brighter children are more curious, which makes them more likely to try pot and alcohol.

The same group of children were less likely to smoke cigarettes however, which researchers believe is due to middle-class parents warning them about the dangers of tobacco use.