Charles Murray has joined the inequality debate with a provocative argument that challenges the prevailing liberal view. He, too, believes there is a class divide in white America, but he contends that it is rooted in cultural, rather than economic, change.

In 1960, Murray says, white Americans shared a common culture. Although some people had white-collar jobs and others had blue-collar jobs, the two groups lived together in the same neighborhoods, shared common experiences, participated in common institutions, and held to a common set of values. But over the past half-century, this culturally monolithic white America has disappeared. In its place, he argues, are two separate and unequal classes, divided by geography, marriage, education, tastes, and values.

At one end of this divide is a new upper class: college-educated, hard-working, affluent, and happily married for the long term. At the opposite end of the divide is a new lower class: less-educated, idle, and episodically married if married at all.

The two classes live in separate communities. They have little regular contact with each other. They rarely meet in the grocery store or the bus stop or the local school or the pews. They have radically different styles of childrearing. The upper class sets strenuous performance and achievement standards for their children while the lower class let the kids play video games.

Murray fears that as the residential separation widens, as common patterns of daily life diverge, and as shared bonds dissolve, the very essence of what makes America America will be lost.

According to Murray, this pattern is the product of a natural “cognitive sorting” of the population by intelligence, higher education, and marriage. He argues that high-IQ individuals who attend the best colleges and universities in the nation and later marry other high-IQ individuals from the best colleges and universities form a genetically privileged elite. This cognitive elite is self-perpetuating. High-IQ parents send their high-IQ offspring to Ivy League schools, where a disproportionate share of the students come from families in the cognitive elite and where many of the elite children will marry other elite children. As a result of “cognitive sorting,” the new upper classes concentrate the pool of the nation’s intellectual capital within their own ranks and accumulate a fund of social capital within their own communities.

Thus, Murray contends, upper-class white America has cornered the market on the good life. Its members are able to get the best jobs, earn the highest incomes, and participate in a lively civic culture and associational life in their segregated enclaves.

And what of the new lower classes? Murray stops short of following the logic of his argument by cognitively sorting the less well-educated into “Dumb America.” Instead, he argues that the new lower classes are on the wrong side of a “values” divide. Murray uses social-science data to argue that the lower classes have retreated from traditional values while the upper classes, after a brief flirtation with countercultural values in the 1960s and ’70s, have embraced them.

For Murray, “marriage has become the fault line dividing American classes.” In the 1970s, the overwhelming majority of white adults ages thirty to forty-nine were married; by 2010, a marriage gap had opened between college graduates and those with a high-school diploma. The college graduates still married at very high levels, but the proportion of married couples with only high-school degrees dropped to below 50 percent. Further, while the college marriages were reportedly happy and stable, high-school marriages were less happy and more likely to end in divorce. Finally, by Murray’s calculation, the rate of births out of wedlock for women who went to college fell in the range of 5–8 percent in 2010, while the rate for women with only a high-school degree was somewhere between 43 and 48 percent. Murray concludes that the decline of marriage among lower-class America is so great that “it calls into question the viability of white working-class communities as a place for socializing the next generation.”

Murray links the retreat from marriage to men’s retreat from industriousness. From 1960 on, working-class men began to drop out of the workforce, even during the years when jobs went begging and unemployment was low. Murray attributes this decline in men’s work ethic to plain old sloth: working-class men started “goofing off” rather than working hard. That being the case, they ceased to be good candidates for marriage. Working-class women, unwilling to wed these slackers, began to give up their dreams of marriage and to opt instead for jobs and for motherhood on their own.

Murray makes a timely and important contribution to the inequality debate by focusing attention on the fragility and insecurity of marriage in white working-class family life—a factor that many liberals have been reluctant to acknowledge as an important part of the inequality story. He also deserves credit for calling attention, however unsympathetically, to the troubles of white working-class men.

Yet his historical argument is cartoonishly simplistic. Drawing on themes favored by conservatives—the moral greatness of the founders; American exceptionalism; the failings of intrusive government and the European welfare state; the pursuit of human freedom as the summum bonum of life—he weaves a story of America’s moral rise and fall. This is a selective history—both in its chronology and its subject matter. He depicts a near universal adherence to the “founding virtues” from the early days of the republic to the mid-twentieth century. Much of this moral progress, he says, is due to the widespread influence on immigrant children of the American schoolhouse and McGuffey Readers. After meandering through the nineteenth century, Murray leaps ahead to the mid-twentieth and to the high point of a common culture.

Oddly, for an avowed libertarian, Murray has deep affection for the communitarian life of the l950s. And indeed, his fond evocation of that time rings true for me—as it will for many Americans who came of age in the middle of the last century. Postwar America was a communal culture, in large measure because of the commonality of life experience: a war fought by Americans of all classes; the return home of millions of GIs; the provision of a generous package of public- and private-sector benefits that fostered marital unions and union jobs; and a growing prosperity for the working and middle class. Unfortunately, Murray fails to acknowledge that economic, governmental, and cultural forces—not simply the practice of the four founding virtues—made up the common culture of that uncommon period.

The 1970s marked the beginning of the nation’s moral descent, Murray says. From that time on, the postwar cultural consensus gradually fell apart. Yet during the same period of time, in Murray’s telling, the nation’s economy had no significant effect on the white working class. Notably, the book’s index has no entries for globalization, deindustrialization, automation, outsourcing, or inflation.

Murray holds out little hope that this decline can be reversed. He calls upon elites to preach to the multitudes the virtues they practice in their own privileged lives. But that’s about as far as Murray’s ideas for reform and renewal can take him. In the final analysis, his theory of a genetically determined class structure leads to the pessimistic conclusion that a remoralized working class, however fervently wished for, is unlikely to appear anytime soon.