Below is an academic journal article which claims that "racists" have low IQs. I append some comments at the foot of it
Bright Minds and Dark Attitudes
Lower Cognitive Ability Predicts Greater Prejudice Through Right-Wing Ideology and Low Intergroup Contact
Gordon Hodson et al.
Despite their important implications for interpersonal behaviors and relations, cognitive abilities have been largely ignored as explanations of prejudice. We proposed and tested mediation models in which lower cognitive ability predicts greater prejudice, an effect mediated through the endorsement of right-wing ideologies (social conservatism, right-wing authoritarianism) and low levels of contact with out-groups. In an analysis of two large-scale, nationally representative United Kingdom data sets (N = 15,874), we found that lower general intelligence (g) in childhood predicts greater racism in adulthood, and this effect was largely mediated via conservative ideology. A secondary analysis of a U.S. data set confirmed a predictive effect of poor abstract-reasoning skills on antihomosexual prejudice, a relation partially mediated by both authoritarianism and low levels of intergroup contact. All analyses controlled for education and socioeconomic status. Our results suggest that cognitive abilities play a critical, albeit underappreciated, role in prejudice. Consequently, we recommend a heightened focus on cognitive ability in research on prejudice and a better integration of cognitive ability into prejudice models.
What the article ignores is that the mental gymnastics required by political correctness are considerable. A simple soul who sees a lot of black crime is likely to have a low opinion of blacks and say so. But, as is often said, some ideas are so stupid that only an intellectual would believe them. And concluding that chronic black criminality is all Whitey's fault is one such idea. So all the study really shows is that brighter people are more able to absorb the counterintuitive but politically correct cult that the elite have made normative in society. Only simpler people take their views from observable reality.
And we must also note that we are talking here about ADMITTED attitudes. And where some attitudes are much decried -- as are racially-denominated attitudes -- the truth of any admissions can only be speculated on. It could well be that attitude to blacks (say) is the same at all levels of IQ but only the simpler members of society are foolish enough to admit what they really think.
I could go on but I think it is already clear that this study proves nothing.