Commenter RR has a left a series of comments on this blog denying the very idea of culture fair IQ tests.

For example he writes:


This is a tautology not a testable hypothesis. The concept of culture bias needs to be operationalized if it wants scientific credibility.

In the field of psychometrics, a test is typically defined as culturally biased if the regression line predicting school performance from IQ is different in one group than another. For example, if blacks with an IQ of 120 get an A in algebra (on average), but whites with IQs of 120 get only a B, then the test is said to be culturally biased against blacks.

Why? Because if the test is underpredicting the grades of black kids, then it’s probably also underpredicting their intelligence as well.

The literature on predictive bias is extensive and it turns out that by this definition, neither IQ tests nor college admission tests are biased against any visible minority group in the United States. Indeed just the opposite, the tests tend to overpredict black achievement, and thus might even be considered biased against whites!

However this definition assumes that the criterion that test is predicting (i.e. school grades) is itself free from bias, but what could be more culturally loaded than school (the place where culture is explicitly taught).

Perhaps a better criterion than school grades would be real world survival skills. We could dump people in the middle of the woods and see how long they take to find their way out (each person would have a GPS locator they couldn’t use but could be used to find them) or have people compete in mock warfare like paintball. Again, if blacks with an IQ of 120 performed as well as whites with an IQ of 120 on these tasks (equating for practice and physical fitness), then IQ tests are unlikely to be culturally biased. But if 120 IQ blacks dominated 120 IQ whites, then it’s likely the tests are underestimating their intelligence.

Another way of testing for culture bias, as Jensen has alluded to, is to compare groups on physiological measures of intelligence like MRI brain size, evoked brain potentials, nerve conduction speed, neural adaptability reaction time etc. Jensen estimates that a comprehensive battery of such tests would correlate > 0.5 with IQ and this would be ideal for testing for culture bias. If for example, the nation of Nepal scored 3.8 standard deviations below the UK mean on tests like the Raven we would want them to take the physiological measure of intelligence.

The > 0.5 correlation would between IQ and its physiological proxies predicts that Nepal would score at least 3.8(0.5) = 1.9 SD below UK norms on physiological measures, but if they would score much better than this (and they would) we would know that the IQ test was culturally biased against them, and thus is dramatically underestimating their neurology.

We can never say, categorically, than any given test is culture fair, but what we can say is that test A is culture fair with respect to cultures B and C. For example in the 1920s it was proven that hardcore performance tests (similar to Block Design and Object Assembly subtests on the WAIS) are culture fair to people with and without schooling. I wrote the following in 2014:

… excellent research in the 1920s showed that canal boat children who lived a nomadic existence where they were virtually deprived of schooling, showed massive declines in IQ as they got older. Because IQ tests are normed for age, and because these kids were kept out of school they fell further and further behind their chronological age-mates on the type of knowledge that IQ tests measure. Young canal boat kids would have an IQ around 90, but older canal boat kids would have an IQ of 60. However in a footnote on page 1001 of this document, scholar Arthur Jensen writes:

When the canal boat children were tested on nonverbal performance tests, there was much less decline in scores and the average IQ of the children was 82, which is a typical value for unskilled workers, as the canal boat people were. Fewer than 1 in 10 obtained performance IQs below 70, and in fact there was a slight positive correlation between performance IQ and age

This demonstrates that some IQ tests really do come close to the culture fair ideal. People understood that in the 1920s, but decades of post-modern propaganda has brainwashed generations of credulous university students into thinking otherwise.