In contemporary America, “the conversation about race” never ends. It fuels political debate and cable chatter, and practically every week some new outrage — real or imagined — is fodder for the hungry maw of the interminable conversation.

We don’t talk about class nearly as often, even though the bifurcation of American life along class lines continues apace, with distressing consequences for the state of the American Dream.

On the heels of conservative scholar Charles Murray’s “Coming Apart,” a much-discussed study of class divisions in white America, arrives “Our Kids” by the respected political scientist Robert Putnam of “Bowling Alone” fame. It paints much the same picture as Murray, with an emphasis on how the differences among high- and low-income parents affect the prospects of their children.

Children of more affluent and better-educated parents have substantial, and growing, advantages, beginning with the fact that they are much more likely to grow up in stable homes.

Over and over, Putnam cites data showing college-educated and high-school-educated parents sliding in different directions.

College-educated mothers delay childbearing about six years later than they did 50 years ago, and thus tend to be better prepared; high-school-educated moms have their kids slightly earlier than 50 years ago, and a decade earlier than college-educated mothers.

Since the 1970s, nonmarital births have increased only a little among college-educated women, while they have risen inexorably among high-school-educated women.

Divorce has fallen among college-educated Americans since 1980, but continued to increase among the high-school-educated.

For all our obsession with race, class is asserting its predominance in these family trends. “College-educated blacks,” Putnam writes, “are looking more like college-educated whites, and less educated whites are looking more like less educated blacks.”

In part because of these family differences, there is an enormous, class-based parenting gap. “Increasingly,” according to Putnam, “parents from different social classes are doing very different things to and for their kids, with massively consequential results.”

More affluent parents tend to have the wherewithal to engage in the intensive nurturing best-suited to giving their children the social, emotional and educational tools they will need to succeed later in life.

“The ubiquitous correlation between poverty and child development,” Putnam writes, “is, in fact, largely explained by differences in parenting styles, including cognitive stimulation (such as frequency of reading) and social engagement (such as involvement in extracurricular activities).”

Again, Putnam demonstrates a growing divide. Family dinners are an important vehicle for conversation between parents and children. They had been declining as a practice since the 1970s, but the slide stopped among college-educated parents in the mid-1990s and continued among high-school-educated parents.

In the 1970s, parents of all classes were spending about the same amount of time with their young kids. Now, college-educated parents spend about 50 percent more time with their infant or toddler on developmental activities like reading. Kids from poorer households make up the time spent without their parents’ attention in front of a TV.

More affluent families have been spending more money on child care and education for their children, while the lowest-income families have been spending less.

The difference in educational achievement between children from high- and low-income families has increased. “This class gap,” Putnam writes, “has been growing within each racial group, while the gaps between racial groups have been narrowing.” According to Putnam, a student’s socio-economic status is now more important than test scores in predicting whether an eighth-grader will graduate from college, a fact that should be a fire bell in the night for anyone concerned about opportunity in America.

What accounts for all these changes, and what policies might make a difference? Those nettlesome, weighty questions seem fit topics for a national conversation. But forgive me, I know we’re supposed to be talking about race. Pardon the interruption.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.