Are racists (and political conservatives) dumb?

I have some doubts about how much faith we should put into tests like the I.Q. Test, but it's surely a measure of a variety of factors relevant to intelligence. A recent study published in Psychological Science, showed that people that score low on the test in childhood are more likely to develop prejudiced beliefs later in life. In addition, the study also found that such individuals were more apt to develop socially conservative politics in adulthood.

One might conclude that people that have prejudiced beliefs and those that have more socially conservative political leanings are dumb. Of course, the data does not directly support that conclusion. At most, the data shows that such people probably wouldn't have scored very high on an I.Q. test as kids. But that's a really interesting finding. The authors of the study (both professors from Brock University) provided the following abstract of their paper:

"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 do you think about this?