[Tennyson]

Sowell's work is a vicious attack against Englishmen. He explains that their original culture is so degenerate that it causes them to become as stupid as American Negroes.

Of course, the theory is ridiculous and Sowell's book was printed simply because he is a Negro (and a "conservative").

However, none of the sociological theories deployed to explain away the W-B IQ difference, including Sowell’s, have disposed of the evidence that genetic factors play a significant role in determining this difference. The following telling points, made by Jensen in The g Factor, represent a summary of this evidence;

1) The W-B IQ difference is greater when subjects are asked to repeat numbers in reverse order (backward digit span), compared to normal order (forward digit span). Jensen regards this is an illustration of “Spearman’s hypothesis” that the size of the W-B IQ difference is proportionate to a test’s difficulty or g loading.

2) Black IQ scores are validated by their correlation with independent measures of educational achievement and job performance. In other words, there is no psychometric evidence that IQ tests are culturally biased against Afro-Americans.

3) Differences in reaction times to elementary cognitive tasks cannot be determined by cultural variables or motivational factors. Blacks, on average, have slower reaction times than whites.

4) The W-B IQ difference has remained unchanged for eighty years, a period of significant environmental improvements for blacks.

5) Recent Asian immigrants, on average, have higher IQ scores than US blacks.

6) The mean IQ difference between black and white children increases at each successively higher level of parental socio-economic status. This phenomenon is only explicable in terms of the genetic law of filial regression to mediocrity, enunciated by Galton. Similarly, when blacks and whites were matched by Jensen for an IQ of 120, their siblings average IQ was found to be 113 for whites and 99 for blacks.

7) There is a pronounced dysgenic trend within the Afro-American community, due to a differential birth rate. This problem is possibly compounded by inbreeding depression, contingent on race differences in sexual behaviour (Jensen, personal communication with the present writer). This dysgenic trend can only enlarge the W-B IQ difference.

8) The Minnesota Transracial Adoption Study demonstrated that adoption of black children by white, middle class families does not lead to significant long-term IQ gains.

9) The W-B IQ difference is not simply a difference in socio-economic status. For as Sowell himself concedes, “Asian American students from families with incomes of $6,000 or less scored higher on the mathematics portion of the SAT [Scholastic Aptitude Test] than black … American students from families with income of $50,000 or more”.

10) Blacks in Africa who have never been subjected to slavery have lower average IQ than Afro-Americans who have. This finding contradicts anthropologist John Ogbu’s ingenious theory that the lower average IQ of Afro-Americans compared to whites is a concomitant of their caste status.

The g Factor: The Science of Mental Ability