Chapter nine deals with how to measure intelligence and trends among people of different levels of intelligence. A very interesting study first published in the Journal of Epidemiology and Community Health seems to suggest that high use of illegal drugs is a trend among individuals with high intelligence. The study measured the IQ of 8,000 participants at ages 5 and 10 and gathered information on self reported levels of psychological distress and drug use at ages 16 and 30. Holding constant for reported anxiety/depression during adolescence, parental social class, and lifetime household income, the study found that men with high intelligence in adolescence were 50% more likely and women with high intelligence in adolescence were more than 50% more likely to use illegal drugs by age 30 than individuals who had low-intelligence in adolescence.
The researchers who headed the study say it is unclear why there is a link between high IQ and illegal drug use but point to previous studies as possibly providing some answers. One such study shows that highly intelligent people are more open to experiences and keen on novelty and stimulation. Another study shows that intelligent children are often easily bored and suffer at the hands of their peers for being different. Researchers say that "either of which could conceivably increase vulnerability to using drugs as an avoidant coping strategy."
However, I still don't completely buy that intelligent people do more drugs. It generally is a common sense things that drugs are a dumb thing to do:
And shouldn't intelligent people have more common sense? Hopefully more studies will follow and conclusively show if and why there is a link between high intelligence and drug use.