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.
Assessing Psyche, Engaging Gauss, Seeking Sophia 
I’d consider adding this: High IQ distorts the context in which one understands intelligence. A high IQ increases the likelihood that one compares their knoweldge to that of others around them, versus to the body of possible knowledge for lower IQ’s. Find the upshot on the hubris/confidence/arrogance scale. My point of view bias: I manage a newsroom and am continually astounded by the professional advantage of those more awed by how much they don’t know than by how much they do.
You might be right! If this advantage exists, it is likely offset by another trend: low IQ is associated with being less accurate in knowing what one does not know.
Maybe. I believe I am less concerned about being more or less “accurate” about what one does not know than I am in being respectful of or awed by the potential scope of what one does not know. My correlation of that to High/Low IQ is just my impresion and might be very tenuous.
Because the majority of us are average–maybe life’s greatest troubling tautology–like watching celebrities make fools of themselves on TMZ, we relish finding the weaknesses of the group of highly intelligent. However as Terman’s longitudinal study showed years ago and Linda Gottfredson has shown more recently, the group of highly intelligent tend to be gifted in a multitude ways, including the quality of their semen. Why an average guy like me may be willing to admit this may one of the gifts of being mediocre, viz., humility.
Thank you, Dr. Schneider
In addition to the sensible hypothesis above, there is also a sociological explanation in that the definition of “criminal” behaviour is highly skewed toward behaviour engaged in by the working class, rather than the often-more-harmful-but-more-subtle criminality of the upper classes. Embezzlement, tax avoidance, ponzi schemes, and other white-collar crimes are not only frequently not investigated by police, but admired by society. We know, for example, that illegal drug use, which gives the lower classes “criminal” records and jail time, is engaged in at the same levels by white and black populations, and the rich use illegal drugs in famous amounts with impunity. Given what we know about IQ and its bias toward income, race, and other social factors, it’s difficult to even separate “actual” intelligence (whatever definition is given to that, whether genetic or otherwise) from everyday adaptive social effects on cognition.