Home » IQ » The Argument in The Bell Curve

The Argument in The Bell Curve

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 252 other followers

Follow me on Twitter

Charles Darwin

Denis Noble

JP Rushton

Richard Lynn

L:inda Gottfredson


600 words

On Twitter, getting into discussions with Charles Murray acolytes, someone asked me to write a short piece describing the argument in The Bell Curve (TBC) by Herrnstein and Murray (H&M). This is because I was linking my short Twitter thread on the matter, which can be seen here:

In TBC, H&M argue that America is becoming increasingly stratified by social class, and the main reason is due to the “cognitive elite.” The assertion is that social class in America used to be determined by one’s social origin is now being determined by one’s cognitive ability as tested by IQ tests. H&M make 6 assertions in the beginning of the book:

(i) That there exists a general cognitive factor which explains differences in test scores between individuals;
(ii) That all standardized tests measure this general cognitive factor but IQ tests measure it best;
(iii) IQ scores match what most laymen mean by “intelligent”, “smart”, etc.;
(iv) Scores on IQ tests are stable, but not perfectly so, throughout one’s life;
(v) Administered properly, IQ tests are not biased against classes, races, or ethnic groups; and
(vi) Cognitive ability as measured by IQ tests is substantially heritable at 40-80%/

In the second part, H&M argue that high cognitive ability predicts desireable outcomes whereas low cognitve ability predicts undesireable outcomes. Using the NLSY, H&M show that IQ scores predict one’s life outcomes better than parental SES. All NLSY participants took the ASVAB, while others took IQ tests which were then correlated with the ASVAB and the correlation came out to .81.

They analyzed whether or not one has ever been incarcerated, unemployed for more than one month in the year; whether or not they dropped out of high-school; whether or not they were chronic welfare recipients; among other social variables. When they controlled for IQ in these analyses, most of the differences between ethnic groups, for example, disappeared.

Now, in the most controversial part of the book—the third part—they discuss ethnic differences in IQ scores, stating that Asians have higher IQs than whites who have higher IQs than ‘Hispanics’ who have higher IQs than blacks. H&M argue that the white-black IQ gap is not due to bias since they do not underpredict blacks’ school or job performance. H&M famously wrote about the nature of lower black IQ in comparison to whites:

If the reader is now convinced that either the genetic or environmental explanation has won out to the exclusion of the other, we have not done a sufficiently good job of presenting one side or the other. It seems highly likely to us that both genes and environment have something to do with racial differences. What might the mix be? We are resolutely agnostic on that issue; as far as we can determine, the evidence does not yet justify an estimate.

Finally, in the fourth and last section, H&M argue that efforts to raise cognitive ability through the alteration of the social and physical environment have failed, though we may one day find some things that do raise ability. They also argue that the educational experience in America neglects the small, intelligent minority and that we should begin to not neglect them as they will “greatly affect how well America does in the twenty-first century” (H&M, 1996: 387). They also argue forcefully against affirmative action, in the end arguing that equality of opportunity—over equality of outcome—should be the role of colleges and workplaces. They finally predict that this “cognitive elite” will continuously isolate themselves from society, widening the cognitive gap between them.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

Please keep comments on topic.

Jean Baptiste Lamarck

Eva Jablonka

Charles Murray

Arthur Jensen

Blog Stats

  • 666,762 hits
Follow NotPoliticallyCorrect on

suggestions, praises, criticisms

If you have any suggestions for future posts, criticisms or praises for me, email me at


%d bloggers like this: