THE POLITICS OF MENTAL
RETARDATION: A TAIL OF THE BELL CURVE
The life of a diversicrat is disagreeable. He is surrounded by irritants. Of them, he finds none more unsettling than race, particularly racial differences. He confronts them daily, on the athletic field, in the classroom, in the workplace and on the street. Most prickly are IQ differences. Intelligence, after all, is the hallmark of our species. The diversicrat twists and strains to explain IQ gaps away, abandoning parsimony for convolution. But he does not stop with explication. He is an ideological crusader. And like most crusades, this one has victims. Sadly, they include the ill-starred and hapless mentally retarded. Their wretched malady is secondary to the fact that they are asymmetrically black.
Nature-nurture issues do not concern us here. We ask how, not why. We accept racial IQ incongruities as facts, noting only that efforts to erase them have failed. The average IQ of East Asians (Chinese, Japanese and Koreans) is about 1/3 standard deviation (SD) or about 5 IQ points higher than that of Europeans. Ashkenazic Jews score higher still. Their mean IQ is about 15 IQ points above that of non-Hispanic whites. In the US, the African American with a mean score of 85 is at the bottom of the cognitive deck. He thus finds himself disproportionately represented among the ranks of the retarded. All this is anathema to the diversicrat.
The black-white IQ gap has been studied and analyzed for more than 80 years. It has outlived sweeping attitude changes, from extreme anti-black discrimination to bias against whites, Asians and males. The billion-dollar Head Start budget has not dented it. Though IQ scores have been rising worldwide for decades (the Flynn effect) the cognitive distance between blacks and whites has remained remarkably constant. In fact, the 1 SD black-white IQ gap is as close to a fundamental sociological constant as we come.
When the IQ of non-Hispanic whites is normalized to a mean of 100 and SD of 15, the African American mean falls at about 85 with an SD of about 13.5. The black IQ distribution both lags behind and is narrower than the white. The small difference in width manifests itself significantly at the bell curve extremes, reducing both the numbers of retarded and exceptional blacks.
Figure 1 shows IQ distribution curves for
African Americans and non-Hispanic whites. The areas under the curves are
normalized to unity, so that the narrower black distribution appears taller. Two
standard deviations from each side of the white mean mark IQ boundaries for
retardation and giftedness. Outside these borders, in the shaded regions, are
the cognitive extremes. There, the areas under the curves represent the
fractions of each group who meet IQ criteria for retardation or giftedness.
(Most striking is the tiny black representation in the gifted region.) The ratio
of areas shows blacks to be 6.1 times more likely than whites to fall below the
boundary for retardation, and 53 times less likely to be gifted. So profound are
the group differences that they are apparent to the man in the street, who
observes a profusion of African Americans at the bottom of the economic and
educational ladders, and a scarcity at the top.
Bell Curve Extremes
At the left tail of the IQ distribution we find the mentally deficient. They mostly are unable to cope with the challenges of life. As children, they require specialized educational services. When the bell curve is politicized these poor souls suffer. We will see how the diversicrat, unable to tolerate racial differences in retardation rates, has worked a miracle cure.
The diversicrat's goal of eliminating racial disparities extends to both tails of the bell curve. On the right he has inflicted less damage. After all, it is more difficult to harm the gifted than the backward. Nevertheless, racial imbalance in programs for gifted and talented students catch his eye. He pressures local school districts to diversify them. Florida's response is typical. When not enough "disadvantaged minorities" show up in programs for exceptional students, Florida kicks in with Plan B (no kidding -- that is what they call it). Plan B makes use of additional criteria such as "leadership potential," "performance evaluation" and "statements of need." It is hard to get worked up about gifted and near gifted children. We know in the long run they will turn out well. We focus instead on the left tail of the bell curve where the real damage occurs.
The education and psychology communities have responded to OCR pressure by reclassifying mentally retarded children -- bureaucracy's version of a cure. Efforts of the Department of Education have reduced the number of mentally retarded children in public schools from approximately 2.2 percent to less than 1.3 percent. The process took less than two decades. Millions of children of all races have been reclassified. They no longer receive appropriate educational services specifically earmarked for the retarded. Jane Burnette in ERIC Digest #E566 describes the curative secret. "Reducing overrepresentation is a matter of creating a successful school environment for all students and accurately distinguishing disabilities from cultural differences." Figure 2 shows graphically how a dose of Government medicine rendered almost half the country's retarded children whole again.
A Brief History of Mental Retardation
As old as man himself, mental retardation defied precise definition until the development of psychometric tools. An early (1910) scheme introduced by the American Association on Mental Deficiency (AAMD) identified levels of retardation by comparing the afflicted at maturity to children at various levels of development. Idiots functioned as 2 year olds, imbeciles between 2 and 7 years, and morons between 7 and 12 years. These terms are now obsolete and considered offensive.
Psychologists recognized fairly early that cognitive deficiency alone does not satisfactorily characterize mental retardation. People with comparably low cognitive capacity often differ in their ability to adapt to the challenges of daily life. A three-part definition of mental retardation evolved to address this issue. It includes childhood onset, cognitive deficiency, and inadequate adaptive behavior. Though this definition preceded the diversicrat, he was quick to use it to his advantage.
With the development of the IQ test by Alfred Binet in 1905, it became possible to quantify intellectual shortcomings. The test dramatically altered methods of diagnosis and classification, and soon became the principal tool for diagnosing mental retardation. By mid-century two of the three criteria for defining mental retardation, cognitive deficiency and age of onset, could be accurately determined, but the assessment of adaptive behavior relied largely on subjective evaluation. Today, the assessment of adaptive behavior still remains fuzzy enough for the diversicrat to work his miracles.
In 1959, AAMD set the IQ threshold for mental retardation at < 85. The civil rights movement of the next decade forced psychologists to rethink this boundary, because half the African American population fell below it. In 1973, responding to this concern, AAMD (by then AAMR) changed the threshold for retardation from IQ < 85 to IQ < 70. The boundary moved south by one standard deviation! The proportion of blacks below the threshold instantly dropped from about 50 percent to 12 percent. Subsequent refinements made it still more difficult to meet the criteria for retardation.
When Binet in 1905 produced the first IQ test, it promised to revolutionize the diagnosis and treatment of mental retardation. A half century later it came under attack for reasons Binet could not have imagined. Could any of the pioneer psychometricians have foreseen Larry P. v. Riles (1979), a California class-action suit that focused on IQ testing of young black children? The court held that IQ tests were not valid for African Americans. It banned California from using the tests for placing black students in classes for the "educable mentally retarded" or equivalent categories on the grounds that the tests were biased. After a series of appeals, the district court ruled that no special education related purposes exist for which IQ tests could be administered to black pupils. Though only a California ruling, the case began a political assault on standardized testing that has spread beyond the IQ test to college entrance exams, promotional exams and more.
OCR detectives uncovered "discrimination" by looking at school records. The offending data appear in Table 1. The irritant is in the last column. Black children were classified as retarded at 1.5 to 2.2 times the rate of whites. OCR ordered the counties to find a "remedy."
Current technical literature still reports mental retardation rates at 2 to 3 percent of the general population The incidence of mental retardation in Maryland's offending counties is significantly lower than that. The districts had reduced the number of mentally retarded children even before they were cited. They failed, however, to selectively reduce retardation rates.
Irrespective of race, we note significant variation in the rate of retardation from county to county. With populations this big, uniform criteria should produce uniform retardation rates. Harford County, a semi-rural mostly white county, reports about 3 times the rate of retardation as the more cosmopolitan Montgomery County and the predominantly black Prince Georges County. A child in mostly white Baltimore County is about twice as likely to be retarded as his peer in the also mostly white Howard County. These discrepancies were less troublesome to the Department of Education than racial issues.
Nationally, about 12 percent of African Americans and 2 percent of non-Hispanic whites have IQs < 70. Not all these people, however, are mentally retarded. Prince Georges County, for example, identified 0.448 percent of its black students and 0.290 percent of its white students as retarded, both numbers well below the number with IQ < 70. A simple calculation shows that only 4 percent of black children and 15 percent of the white children with IQ < 70 were found to have sufficient adaptive behavior deficits to warrant classifying them retarded. On the surface it appears that PG County discriminated against whites, since white children were found to have adaptive behavior deficits at almost four times the rate of blacks. That, however, is not the case.
Among blacks and whites with comparable cognitive deficits, blacks generally show a better ability to adapt to the rigors of everyday life. The difference is pronounced. Arthur Jensen observed in The g Factor that black pupils with IQ deficiencies often socially integrate well with their brighter peers. They seem quite normal when engaging in non-cerebral activities like play. In contrast, many cognitively impaired white children have difficulty integrating socially and often have physical abnormalities such as flat-footed gaits. Jensen attributes this racial divergence to different etiologies that are transparent to IQ tests.
Two types of mental retardation can be differentiated. Organic retardation is due to a genetic anomaly or brain damage brought about by disease or trauma. Familial retardation results from normal variations in intelligence. Among whites with IQ < 70, between 25 and 50 percent are diagnosed as organic. Since 2 percent of whites have IQ < 70, 0.5 to 1.0 percent of the entire white population is organically retarded. Jensen estimates that of the blacks with IQ < 70, only 12.5 percent are organically retarded. (We estimate the number closer to 16.7 percent.) Thus for blacks, we expect 16.7 percent of the 12 percent with IQs < 70 to have organic etiologies. That is, about 2.0 percent of the black population at large is organically retarded. Following Jensen, if we associate most of nonadaptive behavior with organic retardation, then Reference County should classify about 2.0 percent of black children and 0.5 to 1.0 percent of white children as mentally retarded. Blacks in Reference County will be retarded at 2 to 4 times the rate of whites. Table 2 compares the offending counties to Reference County.
From Table 2 we note that the ratio of black to white retarded children is in the expected range for two of the five cited counties, Baltimore and Howard. In two others, Harford and Montgomery, the ratio is only slightly out of bounds. In Prince Georges County the B/W ratio is lower, but still not egregiously so. We safely conclude that the five Maryland school districts did not discriminate against blacks, and that administrators and staff mostly did their jobs conscientiously.
Data in Table 2 also point to a general reluctance to classify any student as retarded, especially if he is black. Only two of the counties, Baltimore and Harford, fell within the expected range for white retardation, 0.5 to 1.0 percent. All of the counties fell below the 2 percent retardation rate expected for blacks. Both sets of numbers reflect the decades-long campaign of the Department of Education to "cure" mental retardation.
In 1998, Marylanders were given a clear philosophical choice when they went to the polls to elect a governor. Glendening (the winner) was an archetypal liberal tax and spender. Sauerbrey (the loser) was a classic hard-right conservative, with a record in the State Legislature to back that up. Huge tax cuts were high on her agenda. She decried a social welfare system run amok, condemned a decline in morality, abhorred abortion in any form, criticized gun control measures and attacked environmental regulations that intruded on property owners' rights. The two candidates agreed on almost nothing. If ever there was a clear philosophical choice, it was in Maryland in 1998.
Because the 1998 election was drawn on such sharp ideological lines, we used election returns for the five counties to come up with a measure of political philosophy. Table 3 compares retardation rates in the five Maryland counties with the percent of the electorate in each county who voted for Sauerbrey. The rank order of retardation rate was identical to the rank order of political conservatism.
The correlation between retardation rate and percent support for Sauerbrey was extraordinary, with correlation coefficients of 0.88 and 0.90 for the black and white rates, respectively. Correlation coefficients this large are almost unheard of in social science. It is a pretty safe bet that right-leaning school districts will find more of their children retarded than their left-leaning counterparts, a fact that leftists have long suspected.