The Bell Curve Chapter 16 Social Behavior and the Prevalence of Low Cognitive Ability

In this chapter, the question is not whether low cognitive ability causes social problems but the prevalence of low cognitive ability among people who have those problems. For most of the worst social problems of our time, the people demonstrating the anti-social behaviors are in the lower portion of the cognitive ability distribution. Practical solutions must therefore be capable of succeeding with such people. In previous chapters ethnic groups other than white were excluded. The data in this chapter are representative of all Americans aged 26 to 33 as of 1990.

In 1989, 11.1 percent of people aged 25 to 34 were in poverty. Forty-eight percent of the poor were from the bottom 20 percent of intelligence. In fact, 32 percent of the poor come from the lowest IQ decile (10 percent) and 48 percent of the poor are from the lowest two deciles. Finally, 80 percent of those impoverished are in or below the fourth decile. These people have IQs of 87 or lower. Only 2 percent of people in the tenth decile, with IQs above 119, are in poverty. The statistics are similar for permanent high school dropouts wherein two-thirds of dropouts come from the bottom 20 percent in intelligence. Overall, 94 percent of permanent dropouts were below average in IQ. On the other hand, intelligence was not a major factor in determining whether men were at work. By and large, men who were employed throughout 1982 were spread across the full range of IQs, with only a minor elevation for those in the top four deciles of intelligence. The authors do not provide an explanation for this finding which is dissimilar to the other conclusions in this chapter. It also if contradictory to the finding that those who did not work at all in 1989 had mean IQs of only 84 and 64 percent of able bodied men who were chronically unemployed were in the bottom 20 percent of intelligence. Now let's consider men and crime. Just who are the criminals? The mean IQ of men locked up in a criminal facility in 1989 was only 84 and 45 percent were in the bottom 10 percent of cognitive ability. A full ninety-three percent of those in prison were in the bottom half of the cognitive ability distribution and 62 percent came from the bottom 20 percent of intelligence. The statistics were similar for women on welfare. The mean IQ of women who ever received welfare was 89. Overall, 85 percent of these women had below average IQs and fewer than 4 percent had IQs in the top 20 percent of the population. For women who were chronically on welfare the cognitive distribution was even lower. A full 57 percent of women on chronic welfare had IQs in the bottom 20 percent of intelligence and 88 percent were in the bottom half of the distribution. What effect does this have on children? The authors start with illegitimacy. The mean IQ of mothers whose children were born out of wedlock was 87 and one out of three was born to mothers in the bottom 10 percent of the intelligence distribution with IQs below 81. With respect to children living with divorced or separated mothers, the women in these single parent families had mean IQs of 93 and 50 percent had IQs in the bottom 30 percent of the IQ distribution. The prevailing notion that separation and divorce are so endemic that they affect everyone more or less equally is wrong as regards cognitive ability. With respect to deprived home environments, the mean IQ of mothers of children in the worst home environments was 86 and three of eight had IQs below 81. Fifty-six percent of all children in the bottom of home environment were born to mothers in the bottom 20 percent of intelligence. Mothers whose children lived in poverty throughout their first three years had a mean IQ of 84 and 41 percent of these mothers were in the bottom 10 percent of cognitive ability. Of all the social problems examined in this chapter, poverty among children was preeminently associated with low IQ, in this case low IQ among the mothers. Most importantly, the authors found that 72 percent of the children in the bottom decile of IQ had mothers in the bottom 20 percent of intelligence. In other words dull mothers beget stupid children. The finding that low IQ mothers have low IQ children should come as no surprise. However, that it is predictable does not make the future for these children any brighter. The authors close this depressing chapter by pointing out that most people in the lower half of the cognitive distribution are employed, out of poverty, not on welfare, married when they have their babies, provide a nurturing environment for their children and are law abiding. However, this does not change the fact that the behaviors and problems of people who dominate the nation's social policy agenda have limited cognitive ability. When the nation attempts to lower unemployment or lower the crime rate or get mothers off of welfare, the solutions must be judged by their effectiveness with the people most likely to exhibit the problems: the least intelligent people. The search for practical solutions to these IQ related social problems are the subject matter of the remaining chapters of The Bell Curve. Comment: It should come as no surprise to the reader, that people who live in poverty or exhibit one or more of the antisocial behaviors have lower IQs than those who are successful in life. Although the authors do not emphasize it in this chapter, our nation's falling mean IQ is a major contributor to almost all of our worsening social problems, including the increasing crime rate, the increasing rate of illegitimacy, the escalating rate of unemployment, and the ever increasing numbers of those who are on some form of welfare. Until we, as a nation, come to grips with, and do something about, the fact that Americans are becoming dumber by the minute, nothing is likely to change. In the closing chapters of The Bell Curve Herrnstein and Murray suggest solutions to the social problems of our time. Unfortunately, I believe, they were far more successful in pointing out the causes of antisocial behavior than they were in suggesting meaningful solutions to the ills that plague our nation.