The widely-cited paper from Hodson and Busseri (2012) shows that low IQ correlates with higher prejudice against races and against homosexuals. In both cases, the relationship is not direct but mainly mediated by right-wing ideology. But this proof is probably an illusion. First of all, let’s examine the key passages :
Hodson, G., & Busseri, M. A. (2012). Bright minds and dark attitudes: Lower cognitive ability predicts greater prejudice through right-wing ideology and low intergroup contact. Psychological Science, 23, 187– 195.
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.
Given that cognitive abilities are critical in forming individuated impressions of other people and in being open-minded (Scarr & Weinberg, 1981) and trusting of other people (Sturgis et al., 2010), individuals with lower cognitive abilities may gravitate toward more socially conservative right-wing ideologies that maintain the status quo and provide psychological stability and a sense of order (Jost et al., 2003). This rationale is consistent with findings that less intelligent children come to endorse more socially conservative ideologies as adults (Deary et al., 2008; Schoon et al., 2010).
The way they have measured their prejudice variable tells us, unfortunately, nothing about the reasons behind the choices made in those questions. To conclude this way is presumptuous. Using a direct question, everyone lies. But using indirect question poses the risk that it will measure something else than what it was supposed to evaluate, across individuals or across groups.
Racism. Attitudes toward racial out-groups were assessed in the NCDS and the BCS with the same five items (e.g., “I wouldn’t mind working with people from other races” and “I wouldn’t mind if a family of a different race moved next door”; αs = .82; Deary et al., 2008; Schoon et al., 2010).
The path correlations shown in their Table 2 indicate that after controlling for conservatism views, intelligence and prejudice don’t correlate anymore. In other words, the major factor was conservatism. In fact, even conservatism was much more correlated with prejudice that IQ itself. It is important to understand what a multiple regression is. especially in the framework of SEM or path analysis, where model equivalency is likely to confound the results. The claim that the effect of low-g on prejudice is mediated by conservatism will be verified only if other pathways can be dismissed on a purely theoretical grounds, e.g., if prejudice or conservatism do not and cannot cause IQ. But if, instead, they can’t reject the equivalent model of IQ->prejudice->conservatism, then their assumption cannot be selected as the best one.
In their conclusion, as displayed below, they argue that a measure of inter-racial contact could also have acted as a mediator in IQ-prejudice correlation. But this depends for the subgroups. Among high IQ people, who live mostly in the safest neighborhood, the inter-racial contact may be of complete different nature as the inter-racial contact for low IQ people who are more likely to live in neighborhood with higher crime rates, which variable correlates with the degree of ethnic minorities.
In a report of a recent American study, Keiller (2010) argued that the capacity for abstract (as opposed to concrete) thinking should facilitate comprehension of other people and the complex mental processing required for the interpretation of relatively novel information (i.e., the type of information encountered during intergroup contact). For instance, adopting another person’s perspective requires advanced cognitive processing, abstraction, and interpretation, particularly when the target is an out-group member (and thus “different”).
However, because intergroup contact is cognitively demanding (Richeson & Shelton, 2003), it may be avoided by individuals with lower cognitive abilities and approached by individuals with stronger cognitive abilities. Furthermore, given that intergroup contact predicts favorable attitudes toward outgroups independently of personal ideology (Hodson, Harry, & Mitchell, 2009), it is possible that such contact uniquely mediates the relation between cognitive ability and prejudice and that this relation is independent of mediation effects through right-wing ideology.
In fact, the main assumption is wrong because their study simply demonstrates that low IQ is linked to conservative view. Nothing more. They fail to establish the causal pathways, where it begins, where it ends. As Gottfredson explained, in Why g Matters: The Complexity of Everyday Life, a higher IQ promotes faster, more extensive, more complete learning and thus a better adaptation to deal with evolutionarily novel, nonrecurrent problems. Low IQ is negatively associated with acceptance of racial groups, not necessarily because low IQ people dislike members of other groups but perhaps because they are reluctant to change (i.e., new ideas, new perspectives). Multiculturalism is a threat to their status quo. The same is true for homosexuality. Both variables can be just a proxy for novelty, changes, and openness to experience.
Dealing with people is cognitively complex, and more so if the persons do not share the same culture. Strangers bring with them new influences, new cultures, new customs, and so on. That’s why low IQ people display less acceptance of other ethnic and racial groups. Nothing to do with hatred. Finally, we should keep in mind that IQ is positively correlated with patience, risk aversion, and cooperation in prisoner’s dilemma games (Frederick, 2005; Dohmen et al., 2007; Oechssler et al., 2009; Jones, 2008; Burks et al., 2009; Benjamin et al., 2013). Those factors may help to understand why high-IQ people have better ability to deal with other ethnic and racial groups.
Thus, to conclude that low IQ people are more hostile to minorities is extremely presumptuous. And unintelligent.