Well I gave myself about a week and I couldn't find the details of the study without paying for them. And I'm not going to pay for them.
I did notice that in the
Live Science article had a reference to the weakness of observational study:
[quote]Hodson and Busseri's explanation of their findings is reasonable, Nosek said, but it is correlational. That means the researchers didn't conclusively prove that the low intelligence caused the later prejudice. To do that, you'd have to somehow randomly assign otherwise identical people to be smart or dumb, liberal or conservative. Those sorts of studies obviously aren't possible.[/quote
That's not entirely accurate. It wouldn't be necessary to randomly assign otherwise identical people. The "identical people" part is just a means of increasing the power. If you randomly assign people without worrying about whether they are "identical" or not and get a "significant" result the results are still sufficient to infer cause and effect. But it does broach the idea that this is an observational study.
Another thing, though, is that a study of this type is extremely vulnerable to bias on the part of the investigator even in terms of how observational studies go. It does not involve and objective measurement such as length or weight. It involves some kind of index of "conservatism" that is entirely dependent upon the investigator. The investigator is in position to increase the odds of obtaining the results he or she wants.
This study did not involve the US population. But if one were to apply the hypothesis that there is negative association between IQ and conservatism in the US one would find that exit polling does not appear to be consistent with that hypothesis. There have been some consistent voting patterns in national elections in recent history and they are opposite of one would expect if lower IQ were associated with conservative positions on issues. Likelihood of voting Republican typically increases as income increases. It also, for the most part, increases as education increases. The exception is at the high end; where a modest majority of those with post graduate degrees typically votes Democrat. But, also, the racial demographics groups characterized by lower than average average IQs tend to vote overwhelmingly Democrat. One exception to that is that Asians tend to vote majority Democrat. But that is a very small (percentage wise) minority group.
All in all, when you look at exit polling, it appears VERY unlikely that the average IQ of those who vote Republican is lower than that of those who vote Democrat. In fact you'd have to say that it is likely that the opposite is the case.
The latest example is provided by exit polling results for the 2010 House elections at
http://www.cnn.com/ELECTION/2010/results/polls/#USH00p1" onclick="window.open(this.href);return false;. Its very clear that the overwhelming majority of the least educated, minority, poor populations voted Democrat. It may not be politically correct to say so, but that pretty much means that the lowest IQ groupings voted overwhelming majority Democrat.
And when you look at those exit polls you are looking at the results of very large scientific samples.
