In a previous post I estimated the average IQ of black Republicans to be only 78. Why such a low number? Because blackness and conservatism both are negatively correlated with IQ, yet because both are negatively correlated with one another, someone unlikely enough to be both should have an especially low IQ.

How accurate was my estimate? Audacious Epigone (whose blog made the HBD 23) writes the following:

Converting Wordsum results into IQ scores with a standard deviation of 15 and on the presumption that the white mean is equivalent to a 100 yields 87.8 for black Republicans and 92.5 for black Democrats.

Now in a previous post I estimated that voters have Wordsum IQs 3 points higher than non-voters. While the blacks in this sample are not necessarily voters, they at least knew enough to say whether they were Republicans or Democrats, but if the sample were expanded to included all the black Republicans and black Democrats who don’t know they’re Republicans or Democrats, the average IQ of both parties would drop by 3 points, giving black Republicans a mean IQ of 84.8 and black Democrats a mean IQ of 89.5.

Now, one study claimed Wordsum correlates 0.71 with IQ. Although, 0.71 is a very high correlation for such a short test, it also implies Wordsum has a lot of inaccuracy which tends to minimize IQ differences. So if black Democrats have IQs 11.5 below the white mean of 100 on Wordsum, they’d likely have an IQ closer to 10.5/0.71 = 14.8 points below 100 on a full IQ test (i.e. 85). Similarly, if black Republicans have IQs 15.2 points lower than 100 on Wordsum, they should be 15.2/0.71 = 21.4 below 100 on a full IQ test (i.e. 79).

So it seems I was correct to conclude that black Republicans have an average IQ in the very high 70s (much lower than the national black average). A couple commenters suggested that black Republicans might have higher IQs than black Democrats. The thinking was that even though conservatism is a sign of low IQ in whites, it’s a sign of high IQ in blacks. While this was a plausible theory, it turns out to be wrong. The lesson is never propose a complex theory when a simple one will do. If conservatism is a sign of low IQ in whites, the default assumption is that it’s a sign of low IQ in blacks. Occam’s razor works!