The Bell Curve Part 111 Chapter 13- Ethnic Differences in Cognitive Ability

In Part 11 the authors addressed social behaviors one at a time and restricted their analysis to whiles. In part 111 they turn to the national scene which means considering all races and ethnic groups. The material is extremely controversial because it deals with the effects of fertility patterns on intelligence and the relationship of low cognitive ability to what has become known as the underclass.

It may surprise the reader to learn that, despite the forbidding air that envelops the topic, the ethnic differences in cognitive ability are neither surprising nor in doubt. Large human populations differ in many ways, both cultural and biological and it should come as a surprise that they might differ in their cognitive characteristics. One message of the present chapter is that such differences in native cognitive ability are real and have consequences. East Asians whether in America or in Asia typically score higher on intelligence achievement tests than white Americans; estimates range from 3 to 10 points. The difference in intelligence between black and whiles in America is approximately one standard deviation or a whopping IQ points. This means that the average white person tests higher than 84 percent of blacks and that the average black person tests higher than 16 percent of the white population. The average black and white differ in IQ at every level of socioeconomic status (SES), but the difference is more pronounced at high levels of SES than at low levels. Attempts to explain these differences in terms of test bias have uniformly failed. In the past few decades the IQ gap between white and blacks has narrowed by approximately three points. The narrowing appears to have been caused by a shrinking number of very low scores in the black population rather than an increase in the number of high scores in the blacks. The debate as to whether the differences in IQ between the races is due to environmental factors or inherited genes remains in dispute but, as we will see, the preponderance of the evidence suggests that the differences in intelligence between the races is primarily a result of inherited genetic factors and not environmental influences. The authors begin this chapter by emphasizing that the IQ differences between individuals of a race are far greater than the IQ differences between ethnic groups. They argue that, even if all the ethnic differences evaporated overnight, most of the intellectual variation in America would endure. The remaining differences in cognitive ability would still strain the political process. In this respect, the authors point out that differences in cognitive ability are a problem even in ethnically homogeneous societies. They assert that the chapters in Part 11, which looked only at whites, should have made this abundantly clear. Following this introduction, the authors provide answers to the most commonly asked questions about the ethnic differences in intelligence beginning with the basics and moving into more complex issues. Because of the recent success of the Pacific rim nations and the success of Asian immigrant children in our schools they begin the discussion by addressing the following question. Do Asians have higher IQs than whites? The answer is yes if we are referring to Japanese, Chinese and Koreans. A 1991 review of the literature reveals that native Chinese have a mean IQ of 110 (the mean IQ of white Americans at that time was 101). The mean IQ of Japanese living in Japan is 103, the same as the mean IQs of Koreans living in North America. What about the differences in IQ between blacks and whites? The answer is one standard deviation. Whites have a mean IQ of 101 while the average IQ of blacks is 85. A review of 156 IQ studies comparing the IQs of blacks and whites in the twentieth century revealed a white/black difference of 1.08 standard deviations, or about 16 IQ points. To get a better understanding of the size of the IQ gap between whites and blacks consider this statistic. A black person with a mean black IQ of 85 would be in the lower 11th percentile of a white distribution and a white person with an average IQ of 101 would be in the top 91st percentile of a black distribution, if they were black. This does not mean, of course. that there are not many extremely smart blacks. In the early 1990s, when The Bell Curve was written, the black population numbered over 30,000,000 about 100,000 of whom had IQs that were in the highest cognitive class ( very bright) with IQs of 125 or greater. One hundred thousand is a lot of people and it should come as no surprise to see blacks functioning at high levels in every intellectually challenging field. Critics of IQ test argue that the tests are loaded culturally in favor of whites. For example, in a SAT test this analogy item has become famous as an example of cultural bias. Runner: Marathon (A) envoy: embassy (B) martyr: massacre (C) oarsman: regatta (D) Referee: tournament (E) horse: stable The answer is pretty obvious but how likely is it that black youngster from an inner city slum would ever have heard of a regatta? If not, the answers to questions like this would be little more than guesswork. The fact is, however, that the studies of possible test cultural bias have lead the authors to the opposite conclusion because the findings indicate that the white/black differences are wider on items that appear to be culturally neutral than on items that seem to be culturally loaded. In any case, there is no longer a technical debate over the conclusion that the cultural content of test items is not the cause of group differences in test scores. However, just because the tests are not rigged to favor whites does not mean that cultural differences in the white and black communities do not give whites a leg up when it come testing for intelligence. Maybe blacks do not perform well on such tests because they lack the motivation to do so, after all education is thought to be "a white man's thing" in large segments of the black community. Two tests dispel this myth. the first involves the forward digital span test in which the subject is asked to repeat a series of numbers in the order read to him; the second is the backward digital span test in which the subject tries to repeat a series of numbers backward. The test is not culturally biased because it uses numbers that are familiar to everyone and calls on no cultural information besides knowing numbers. The backward form is twice as g-loaded (general intelligence) as the forward form. The reason is that reversing the numbers is more mentally demanding than simply repeating them as heard. In most of these studies the black/white difference is about twice as great on the backward digits as on the forward digits. This observation is of upmost importance because how can lack of motivation, willingness to take the test, or any other plausible explanations explain the difference in performance on the two parts of the same sub-test? Obviously they can't! Similar questions arise from work on reaction time Arthur Jensen postulates that neurologic processing speeds, akin to the speed of a microprocessor on a computer is a indicator of general intelligence- g. The smarter the subject is the faster is his reaction time to simple tasks such as turning off of a console with a series of lights. One such device has a home central home button surrounded by 8 lights. The subject starts the test by hitting the central button to turn on one of the 8 surrounding lights and ends the test by hitting a second button closest to the light that has been turned on. There are more complicated versions of this test but none require much thought and primarily measure reaction time. We see a variation of this test everyday at street stop lights. There is a reason some people take forever to get their cars moving after the light turns from red to green (my observation not the authors). In any case, reaction times have been correlated with tests measuring general intelligence. The consistent result of such studies is that white reaction time is faster, on average, than black reaction time. Other kinds of bias include the possibility that blacks have less access to coaching than whites, less experience with tests, poorer understanding of standard English and are subject to the bias of white examiners. Each of these hypotheses have been investigated for many years, under many conditions, but none have been found to have merit. Having put to rest the possibility that tests designed to measure racial differences in intelligence are biased, the authors tackle and even larger question. Are differences in overall black and white test scores attributable to differences in socioeconomic status? This question has two different answers depending on how the question is understood, and confusion is rampant. Many people suggest that what appears to be a racial difference in IQ scores actually is a socioeconomic difference. In a regression equation in which includes both race and socioeconomic status, the differences between whites and blacks shrinks to .76 standard deviation. Such studies would suggest that the 37 percent of the original B/W intelligence gap is a result of socioeconomic influences and not genetically inherited factors. The problem with this line of reasoning is that socioeconomic status, in its self, is a result of cognitive ability since people of high and low intelligence have correspondently high and low places on the socioeconomic ladder. Because of these complex relationships, "controlling" for socioeconomic status in racial comparisons is guaranteed to reduce the IQ differences in the same way that choosing black and white samples from a school for intellectually gifted children is guaranteed to reduce IQ differences (assuming race-blind admission standards. Looking at it from another angle, suppose we attempting to determine whether blacks were faster sprinters than whites but only examined Division 1college athletes. In other words the test subjects had already been preselected for their sprinting ability. Blacks, on average, would sprint faster than whites but it would be a smaller difference than in the population at large. The simplified answer to the question of socioeconomic bias in IQ testing is this. People who live in slums are there because their ancestors, on average were dumber than the ancestors of those who live in the suburbs. The inner city blacks do not perform well on tests of IQ, not so much because they are disadvantaged, but because they are intellectually inferior, on average, to their white counterparts. This is my conclusion, not that of the authors. The authors next pose an interesting question. As blacks move up the socioeconomic ladder, do the intellectual differences with whites of similar socioeconomic status diminish as they should if variations in IQ were primarily caused by environmental factors. The rational goes like this: Blacks score lower on average because they are disadvantaged due to their environment, poverty, poor schools, bad parenting, etc. This disadvantage should most seriously handicap black children in the lower socioeconomic classes where their living conditions are the most dire. As blacks advance up the socioeconomic ladder, their children who are less exposed to these environmental defects, will do better and close the cognitive gap with white children of their class. Although reasonable, this expectation is not borne out by the data. IQ scores increase with economic status for both races, but the magnitude of the B/W difference in intelligence, about one standard deviation does not change. Indeed, it gets larger as groups of people move up the socioeconomic ladder. You may be wondering how African-Americans compare with blacks in Africa on Cognitive tests. A 1991 review of the literature reveled the mean IQ of African blacks to be 75, approximately 1.7 standard deviations below American whites and about ten IQ points lower than American blacks. The IQ of "colored" students in South Africa, of mixed racial background, has been found to similar to American blacks. The authors end the chapter on the ethnic differences in cognitive ability by asking, and answering, four pertinent questions. Are Jews really smarter than everyone else? Where do Latinos fit in? What about women versus men? Jews, especially Ashkenazi Jews of European origin, test higher than any other ethnic group( this should come as no surprise to the reader since 23 percent of all the worlds billionaires are Jews even though they constitute only 0.02 percent of the population). Jews in America and Britten have a mean IQ somewhere between a half and a full deviation above the mean. This means that the average western Jew has an IQ between 108 and 116( a third of my medical school class was Jewish and this undoubtedly was the reason). For Latinos, their mean IQs fall about half to one standard deviation below the national mean. The IQ gap between Mexican Americans and whites is .84 standard deviations or about 14 IQ points. In this respect, Latinos are only marginally smarter than blacks. When it comes to gender, males and females have nearly identical mean IQs but men have a broader distribution. The wider distribution (bell curve) for men means that there are fewer really brilliant women than men and there are more really dumb men than women. These differences, however, are small and, for practical purposes, are insignificant. Comment: This chapter on ethnic differences in cognitive ability is the longest in the book, encompassing 46 pages. The authors document in great detail the numerous studies, 157 of them, that lead to the inescapable conclusion that Jews are the smartest people to ever walk the face of the earth and blacks, whether they live in Africa or American are the dumbest. Whites fall somewhere in between and Asians are marginally smarter than whites. Herrnstein and Murray, in their never ending attempt to be politically correct, conclude that genes are responsible for about 60 percent of the racial differences in IQ and environmental factors are to blame for the remaining 40 percent of the IQ gap between the races. I conclude that the genetic influence of cognitive ability is closer the high end of the spectrum or around 80 percent. Whatever the correct figure may be, the inherited genetic influence on IQ is certainly not zero as most academics believe today. The authors also conclude, that even if all the data on cognitive racial differences is erroneous and environment factors play a major, or even singular role, in determining the measured differences in intelligence among the races, nothing can be done to chance the situation. I couldn't disagree more with this conclusion. We could start by paying low IQ women, those on welfare, to take a Norplant injection that would prevent pregnancy for five years; rather, as we do now, pay them to have more and more low IQ children. In this respect, hundreds of billions have been spent on programs such as school busing, head start and school nutritional programs, all of which are designed to level the environmental playing field and all of which have been miserable failures. These programs may improve the lives of those involved but they have had little or no effect on the cognitive ability of our nation.