Charles Murray’s recent book Coming Apart has gotten a lot of attention because of the data it presents concerning the growing social and economic gap between working-class and middle-class people (politicians call all nonwealthy Americans “middle class,” but that is because politicians in a democratic society need to flatter the masses in order to get elected). The incomes of working-class people have fallen, family stability and employment have declined, and the crime rate has risen, creating a very large gap in these respects between working class and middle class, especially upper middle class. As summarized by the Washington Post’s economic analyst Robert Samuelson, “Among those 30 to 49 in the blue-collar community, 84 percent were married in 1960 and only 48 percent in 2010. In 1962, 96 percent of children were living with both biological parents; by 2004, the proportion was 37 percent. Meanwhile, the share of households with someone working at least 40 hours a week dropped from 81 percent in 1960 to 60 percent in 2008.” The middle class and especially the upper middle class have escaped these trends. Murray’s book is not very analytical, however, and also (though this is a limitation more than a defect) contains no constructive proposals for narrowing the class divide—both points argued in a recent online review of the book by David Frum. As Becker points out, the proposals that Murray made in a March 7 New York Times piece are unhelpful.
A significant causal factor in the growing class divide reported in Murray’s book may be the increasing return to IQ. In a society in which most work is manual (for example, agricultural labor, construction of buildings and roads, mining, assembly-line manufacturing, old-fashioned soldiering, and craft work such as plumbing and carpentry), the demand for manual labor is great, and the return to personal qualities that enhance the productivity of a manual laborer, such as physical strength and tolerance for dirty or dangerous working conditions, is substantial and favors men, because they have superior aptitude for most manual labor. (Male upper-body strength in particular is substantially greater than female.) Women have the superior aptitude for household labor, including child care, and so do not compete with men in the labor market in an economy dominated by manual labor.
With technological advance, the market value of the traditional male labor assets—assets that are not correlated with IQ—declines, and men find themselves competing with women for service jobs, which grow relative to mining, manufacturing, and other heavy-duty traditionally male jobs. Hence working-class male incomes fall, and at the same time middle-class and especially upper middle-class incomes rise because the return to IQ rises with the increase not only in technologically complex jobs but also in managerial and other intellectually demanding service occupations. Society becomes more complex and increasing complexity increases the demand for IQ even if the complexity is not technological.
IQ is normally distributed, with a standard deviation of 15 from its arbitrarily scored mean of 100 (not a “score,” really, but just a round number to designate the mean). Hence two-thirds of the population has an IQ between 85 and 115. Persons with an IQ below 85 are pretty much limited to working-class jobs; but that is probably also true of a majority of persons with an IQ between 85 and 100—and persons with IQs below 100 comprise half the population. The percentage of the population with IQs between 70 and 130 (two standard deviations from the mean) is 95 percent, which means that only 2.5 percent have an IQ above 130. The increased return to IQ provides far more opportunities to that intellectual elite than in a society in which the overwhelming demand is for manual labor, and in which the demand for high-IQ persons is largely limited to priests and tyrants.
Of course there are people with modest IQs who are immensely successful, including professional athletes and entertainers (though only a small minority command high incomes in either group). There are even very successful businessmen who owe their success to charisma or even sheer luck rather than to a high IQ, and there are a fair number of dopes who are in the upper middle class by reason of inheritance. And there are high-IQ people who are held back by poor physical or mental health. All this is just to say that IQ is by no means a conprehensive index of personal success; it does not even measure all dimensions of intellectual prowess. There is certainly no one-to-one correlation between IQ and income or family stability or crime, but IQ is an important factor in success in these domains.
If this analysis is correct, then (it seems to me) an essential means of narrowing the class divide, if that is thought an important goal, is redistributive tax and spending policies (which are costly, hence not worth undertaking if narrowing the class divide is not deemed important). Improving our educational system, even if possible, which it doesn’t seem to be, wouldn’t do much, because education can’t do much to increase intelligence. Milton Friedman used to say that the problem of poor people is that they don’t have money, and he advocated a negative income tax (which we now have in the form of the Earned Income Tax Credit). Increasing the income of the depressed working class might go far to increase family stability in that class, lower the crime rate, and perhaps even increase employment, provided the redistribution was coupled with the creation of incentives for working.