December 19, 2011

The seven percent solution

The good lifeThe list of beneficial effects of intelligence is pretty long: childhood IQ predicts health, longevity, education, salary, and protects against suicide, homicide and a variety of ills like divorce. Cognitive ability also makes people better at handling economic games, thinking long-term and cooperatively.

A new study shows that the picture is more complex: James White, G David Batty, Intelligence across childhood in relation to illegal drug use in adulthood: 1970 British Cohort Study, J Epidemiol Community Health (2011). doi:10.1136/jech-2011-200252

They looked at use of illcit drugs among a cohort of 8,000 born in 1970.

When intelligence was factored in, the analysis showed that men with high IQ scores at the age of 5 were around 50% more likely to have used amphetamines, ecstasy, and several illicit drugs than those with low scores, 25 years later.

The link was even stronger among women, who were more than twice as likely to have used cannabis and cocaine as those with low IQ scores.


The findings held true, irrespective of anxiety/depression during adolescence, parental social class, and lifetime household income.


Why? A likely guess is that smart people are novelty seekers - they figure out things more quickly and hence get bored at school and jobs not tuned to their abilities, but they might also become smarter just because they try new things and hence have educational experiences. The paper also suggests that some might feel stigmatized by their peers. Yesterday I saw the new Sherlock Holmes film, and one can certainly see how these explanations fit into our culture.

Another interesting thing the study itself is silent on, but is worth investigating, is whether higher intelligence protects from the health effects of drug use. Smarter people generally have better health behaviours and better health (including both lower incidence of smoking and easier smoking cessation). I would conjecture that cognitive ability helps people manage their drug use, making it less likely to turn into abuse. We'll see.

Posted by Anders3 at December 19, 2011 08:52 PM