Conservatism and cognitive ability are negatively correlated. The evidence is based on 1254 community college students and 1600 foreign students seeking entry to United States' universities. At the individual level of analysis, conservatism scores correlate negatively with SAT, Vocabulary, and Analogy test scores. At the national level of analysis, conservatism scores correlate negatively with measures of education (e.g., gross enrollment at primary, secondary, and tertiary levels) and performance on mathematics and reading assessments from the PISA (Programme for International Student Assessment) project.
The full article is not accessible without pay, and to be honest, I'm not that interested. The level of debate it might provoke is almost certain to dive down to subterranean levels within picoseconds. And certainly, without being able to read the article in full I have no idea what their definitions of 'Conservatism' include, nor the degree of negative correlation, nor the statistical approaches used.
I do note the sample size is pretty decent, and the use of college students and foreign-entry students pretty well rules out this being a sample of down-home Cletus the Yokel types. Of course, going through community colleges is an interesting choice, and naturally one has to wonder what kind of stats you'd get in the Ivy Leagues and so forth. Nevertheless, it's a bold, interesting statement -- all the more interesting since it appears to originate from notoriously-conservative Singapore.
I also wonder, naturally, what would happen if they broke the picture down to differentiate between fiscal conservatism and social conservatism. I certainly see a difference there, at any rate.
In any case, it's worth a laugh, eh? No doubt it's all part of that infamous world-wide conspiracy of left-wing acadaemia...