Bell Curve

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WMDs in progress, proceed with caution.

A proposal by Herrnstein and Murray that white people are smart and colored people are dumb, because of different genes. It was published in 1994.

Their results can be summed up in one sentence: Bad Science leads to Bad Conclusions.

A clear case of penis envy.

Assumptions of the Bell Curve

1. IQ score is a measure of intelligence
a.Intelligence is a number
b.Intelligence is a linear quality
c.Intelligence is a genetic quality
d.Intelligence is immutable

2. Generalising within group differences and comparing them to between group differences.
This ignores data such as these[1]:
a. During World War II, both black and white American soldiers fathered children with German women. Thus some of these children had 100 percent European heritage and some had substantial African heritage. Tested in later childhood, the German children of the white fathers were found to have an average I.Q. of 97, and those of the black fathers had an average of 96.5, a trivial difference.
b. If European genes conferred an advantage, we would expect that the smartest blacks would have substantial European heritage. But when a group of investigators sought out the very brightest black children in the Chicago school system and asked them about the race of their parents and grandparents, these children were found to have no greater degree of European ancestry than blacks in the population at large.
c. Blood-typing tests have been used to assess the degree to which black individuals have European genes. The blood group assays show no association between degree of European heritage and I.Q. Similarly, the blood groups most closely associated with high intellectual performance among blacks are no more European in origin than other blood groups.
d. An adoption study carried out at Arizona State University by the psychologist Elsie Moore, looked at black and mixed-race children adopted by middle-class families, either black or white, and found no difference in I.Q. between the black and mixed-race children. Most telling is Dr. Moore’s finding that children adopted by white families had I.Q.’s 13 points higher than those of children adopted by black families. The environments that even middle-class black children grow up in are not as favorable for the development of I.Q. as those of middle-class whites.

3. Absence of construct validity of Spearman's g
ie there is no evidence that it measures what it purports to measure. They also ignore the criticisms of expert psychometricians like Neisser.Positive correlations between mental tests do not give any information about causality (Statistics 101)

4. Cultural bias in IQ tests
Bell Curve analysis is based on the Armed Forces Qualifying Test (AFQT) which is not an IQ test but designed to predict performance of certain criterion variables. The math section requires high school algebra. Hence the key finding of the Bell Curve (IQ as a predictor of SES) is an artifact of the method.

5. Poverty as a determinant of IQ
Women who score lower than men in IQ tests would have to be 41 points higher than a man to have the same risk of being as poor as him. Gender is completely ignored in the Bell Curve, along with such salient points.* WARNING: TOTAL BIAS FOR OPPRESSION OF WOMEN STANCE*

6. Caste effects on IQ score
Minority status as in conquered populations or through social stratification can have a negative impact on IQ score. This is easily shown when compared to immigrant IQs of the same caste.


Retrospective analysis of the data suggest a deliberate bias in presentation, analysis and inference and indicate the entire thing should be chucked in the bin. Or force fed to those still promoting it.


  1. Herrnstein and Murray, The Bell Curve, 1994[2]
  2. Matthews, A Review of the Bell Curve, 1998[3]
  3. Nisbett, All Brains are the same Color, 2007[4]