"For the study, researchers tracked 6,000 U.K. teenagers' use of tobacco, alcohol and pot from the ages of 11 to around 20. During their early teens, brainy pupils were less likely to smoke cigarettes than their less academically gifted peers, but they were more likely to say they drank alcohol during this period. They were also more likely to say they used cannabis, but this wasn’t statistically significant."
"However, by the time the students hit their late teens, the school-smart ones were 50% more likely to use pot occasionally and nearly twice as likely to use it persistently than those who didn't do as well at school. They were also more than twice as likely to drink alcohol regularly."
http://time.com/4678433/brainy-teens-smoke-tobacco-pot-study/