“As I have shown in many previous chapters, individual differences in intelligence matter in work, school, and everyday life, and these differences have important consequences. One consequence is that people have difficulty imagining what the thought process is like for someone whose IQ is more than about 10 or 15 points away from their own (Detterman, 2014). This causes problems when people at one IQ level make judgments of or recommendations to people whose IQ is very different from their own because people project their level of competence onto others.
This is a special form of what is called the psychologist’s fallacy (a term first coined by James, 1890, p.196), which is the tendency of a person to assume that others think and act more-or-less the way that they do. Ironically, highly intelligent people are one of the groups most susceptible to this blind spot in their thinking.2 Bright people tend to believe that everyone thinks and solves problems as well as they do, and this can have important consequences when high-IQ people deal with other segments of the population.

2 Another group that is highly susceptible to the psychologist’s fallacy is people with antisocial personality disorder, which is characterized by (among other behaviors) a willingness to take advantage of others, a propensity to break rules and laws, and a lack of remorse for hurting others. People with this disorder are sometimes genuinely surprised that other people do not have their same lack of morality and empathy towards others.”