The Bell Curve as Wrong Science - Cavalli-Sforza

Cavalli-Sforza on “The Bell Curve”
bagond, Mon 7 Mar 2011

Luigi Luca Cavalli-Sforza, a Stanford geneticist, said in 1995 that “The Bell Curve” (1994) by Charles Murray and Harvard psychologist Richard J Herrnstein is wrong on the science.

Murray and Herrnstein said that IQ is about 60% genetic. That was the best value as of 1976. Since then several important papers, particularly Rice, Cloninger and Reich (1980), have come out showing that the true number is about 33%.

Cavalli-Sforza says that the best known way to to tell how much genes affect something like IQ is to do adoption studies and then run the numbers throughpath analysis. At first that did give a number close to 60%, but since 1980 it has been repeatedly turning out numbers close to 33%.

Cavalli-Sforza:

It is somewhat disconcerting that all these papers are totally ignored in “The Bell Curve”…. Researchers who might be called “IQ hereditarians” are in general reporting high heritabilities for IQ without any information on how these calculations have been obtained, or why the other papers here cited have been ignored. It is unlikely that they were not seen or read; they are published in well-known scientific journals.

But even if we assume that IQ is 60% genetic between parent and child,that still does not mean the difference between blacks and whites is mainly genetic.

Height, for example, seems to be much more genetic than IQ and yet people in Europe are much taller now than 200 years ago. Since there has been almost no change in the genes of Europeans in that time, the difference is pretty much 0% genetic. Despite height being highly genetic.

Murray and Herrnstein know this and admit this, yet they still say it is “likely” the difference in IQs between blacks and whites is mostly genetic.

Which is pretty strange when they themselves admit that SAT scores between blacks and whites have narrowed by 30% in the past 19 years. At that rate there will be almost no difference in 70 years. It is not as if they think the SAT is not a good rough measure of intelligence.

Cavalli-Sforza thinks almost none of the difference is genetic: both the American adoption study by Sandra Scarr and Barbara Tizard’s study of British orphans showed that when blacks and whites are brought up under the same circumstances the difference pretty much disappears.

He further points out that:

the charts are misleading,
correlation is not cause and that
the g factor is likely a statistical artefact.
He thinks IQ tests measure a small and rather uninteresting part of intelligence and that it is impossible to make one that is reasonably culture-free.

He also says that Murray and Herrnstein are racists. He is the first white author I have read who says that flat out. He says racism is:

the persuasion that some races are definitely better than others in some socially important ways, and that the difference is of genetic origin.

Murray and Herrnstein certainly think IQ is socially important, that whites have more of it and that it is mostly genetic. Therefore they are racists. Even though they talk as if racism has pretty much disappeared.

See also:
Cavalli-Sforza on race and racism
Anti-black racism as a guide to science
HBD
The Bell Curve
Thomas Sowell on “The Bell Curve”
Howard Gardner on “The Bell Curve”
Orlando Patterson on “The Bell Curve”
Stephen Jay Gould on “The Bell Curve”