Agree neolara. A quick search found this:
The Chitling IQ test
"One facetious attempt to develop an intelligence test that utilizes distinctively black-ghetto experiences is the Chitling Test. It is a humorous example that demonstrates well the built-in cultural bias found in most IQ tests. The Chitling Test (formally, the Dove Counterbalance General Intelligence Test) was designed by Adrian Dove, a Black sociologist. Aware of the dialect differences, he developed this exam as a half-serious attempt to show that American children are just not all speaking the same language. Those students who are not "culturally deprived" will score well. "
Also
"Other, similar tests have been developed for Blacks (for example, the Black Intelligence Test of Cultural Homogeneity by Robert L. Williams) and for the Chicano culture and the Redden-Simons Rap Test.
The Redden-Simons "Rap" Test is a 50-item, multiple-choice test of vocabulary items typical of "street language" in 1986, in Des Moines, Iowa. On the short version of the Redden-Simons "Rap" test (12-items), "street" individuals averaged eight correct items, and college students averaged only two correct items.
Using "street" norms, any student who does not get at least five items correct is mentally retarded."
And this is the point about my son really. If you could find a way to measure his visual intelligence without using language he would outperform all of us by some distance.