IQ is positively correlated with almost everything that is good in life and negatively correlated with almost every bad outcome you can think of. The reasons for these correlations are diverse and often surprising.
Though high IQ is generally associated with positive outcomes, it is associated with a few negative ones. It is unknown how many there are but the list is surely very short. Here are some of them:
- People with high IQ tend to be nearsighted. The higher the IQ, the more likely the person is going to need glasses. Some stereotypes exist for a reason! Why the association exists is anyone’s guess…and many guesses have been made. The most amusing hypothesis I have found is the idea that big brains squish the eyes! One thing that is clear is that the correlation is not due to excessive reading.
- People with high IQ tend to have allergies. Another stereotype! However, the evidence for this finding is somewhat mixed. Perhaps there is some sort of trade-off: You can either distinguish between good and bad foreign particles or you can distinguish between good and bad ideas.
- People with high IQ are more likely to commit suicide? The evidence for this finding is mixed and sometimes in the opposite direction, probably because the relationship IQ and suicide is non-linear and moderated by a number of demographic and cultural factors. My guess is that some people who know that they are talented feel worthless when they have failed to live up to expectations (both their own and other people’s).
A new study suggests that this list might get a little longer (sort of). It is well known that IQ and criminality are negatively correlated and that high IQ appears to be associated with lower levels of criminality even among those otherwise at higher risk of becoming criminals. However, a new study by Hampton, Drabick, and Steinberg suggests that, all else equal, high IQ, among people with psychopathic tendencies, is associated with higher levels of criminal offending.
My interpretation of this is that high cognitive ability is neither good nor bad. Rather, it simply allows you do more of what you want to do. In a well-regulated society in which incentives are properly aligned with good behavior, high intelligence will correlate with good behavior. However, in certain contexts (e.g., criminal organizations and dictatorial regimes), high intelligence amplifies one’s capacity to do harm.