By the age of 30 around one in three men in the study had
smoked cannabis
By the age of 30 around one in three men in the study had smoked cannabis

Clever children 'likelier to take drugs'


Steve Connor
Tuesday 15 November 2011 01:00

Intelligent children are more likely than their less intelligent peers to use illegal drugs in later life, according to a study which has found a link between high IQ scores and drug misuse.

Children who were in the top third in terms of IQ when aged five and 10 were found to be at significantly increased risk of having taken illegal drugs such as cannabis and cocaine when they became older.

The study was based on interviews with nearly 8,000 people who were part of the 1970 British Cohort Study, which involved measuring IQ scores when each child was five and 10, and asking them about their drug habits when they were 16 and 30.

By the age of 30, around one in three men (35.4 per cent) and one in six women (15.9 per cent) had used cannabis while 8.6 per cent of men and 3.6 per cent of women had used cocaine in the previous 12 months, the study found. A similar pattern of behaviour was found for other drugs, such as barbiturates, LSD and heroin. Boys in the top third in terms of IQ when aged five were about 50 per cent more likely than the bottom third to have used drugs such as amphetamines and ecstasy when aged 30.

The effect was even stronger among women. High-IQ women were more than twice as likely as low-IQ women to have used cannabis and cocaine in the past year, for instance.

James White of Cardiff University, who led the study in the Journal of Epidemiology and Community Health, said that because the effect could be picked up at the age of five, before schooling, it may be independent of education.

"The study just looked at whether you had or had not used drugs in the last year. We don't know the level of usage and we don't know the harm of low-level drug use," Dr White said.

One possible explanation is that more intelligent people are more likely to get bored or to suffer at the hands of their peers, either of which could lead to experimenting with drugs, he suggested. Overall, high-IQ people are more likely to have healthier lifestyles because they are better informed about diet and exercise, he added.

Register for free to continue reading

Registration is a free and easy way to support our truly independent journalism

By registering, you will also enjoy limited access to Premium articles, exclusive newsletters, commenting, and virtual events with our leading journalists

Already have an account? sign in

By clicking ‘Register’ you confirm that your data has been entered correctly and you have read and agree to our Terms of use, Cookie policy and Privacy notice.

This site is protected by reCAPTCHA and the Google Privacy policy and Terms of service apply.

Join our new commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies


Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in