Robert D. Putnam is technically a Harvard social scientist, but a better description might be poet laureate of civil society. In successive versions of “Bowling Alone” (as a 1995 article and an instant-classic book), Putnam argued, to bipartisan acclaim, that civic life is declining with ominous consequences. Bill Clinton brought him to Camp David. The campaigns of Al Gore and George W. Bush sought his advice. Barack Obama gave him a medal.

If rock star status seems improbable for a numbers-crunching academic — well, it is. But by focusing on sports leagues and volunteer work, “Bowling Alone” let liberals highlight social needs without conjuring big government, while conservatives could signal compassion without delving too deeply into racial or class injustice. A catchy title helped.

In “Our Kids,” Putnam brings his talent for launching a high-level discussion to a timely topic — the state of upward mobility. Widening income gaps, he argues, have brought profound but underappreciated changes to family life, neighborhoods and schools in ways that give big advantages to children at the top and make it ever harder for those below to work their way up.

The idea that growing inequality will hurt upward mobility might seem self-evident. But the academic verdict on intergenerational trends is still out, and data on today’s children will lag for decades. Likening the problem to climate change, Putnam says we can’t wait for perfect clarity but must act now to save the American dream.

You’d never know from “Our Kids” just how radically income inequality has grown; how much influence the wealthy now exercise in politics; and how well they protect their stakes. (We do hear a lot, by contrast, about the importance of family dinners.) To frame inequality, as Putnam largely does, as a product of inadequate empathy and weakened civic institutions is to overlook the extent to which it’s also a story about interests and power.

Where Putnam succeeds is in describing the diverging life chances of children in rich and poor families. (“Rich” parents finished college; “poor” parents have high school degrees or less.) The point isn’t just that rich kids have advantages but that their advantages are large and growing.

A majority of rich kids still grow up with two parents. For poor kids that’s increasingly rare. Rich kids get almost 50 percent more nurturing time from their parents, when there used to be no class difference. Rich kids have a growing edge in access to good day care. The children of less ­educated parents “are increasingly entering the world as an unplanned surprise.”

 

Credit…Brian Stauffer

On it goes as Putnam charts class advantages that start in the womb and widen at every stage. He is particularly troubled by the class differences in the prevalence of family meals, citing evidence that family dining promotes good grades and behavior.

Education is supposed to help level the playing field. Horace Mann called it the “great equalizer.” Now it’s closer to the great fortifier — compounding the advantages of class, since the affluent come better prepared and more able to pay. A few decades ago, the gap between rich and poor kids in finishing college was 39 percentage points. It’s now 51 percentage points. Even poor kids with high test scores are slightly less likely to get degrees than rich kids with low scores. Putnam rightly calls this “shocking.”

Putnam more than makes his case; no one can finish “Our Kids” and feel complacent about equal opportunity. Still his perspective is modestly skewed by two tendencies. One is nostalgia. In terms of college access, Putnam says there was “no trace of bias against kids from humbler backgrounds” in 1959 when he graduated from high school in Port Clinton, Ohio. None? “Few of our families were poverty-stricken,” he writes, though child poverty was 7.4 percentage points higher nationwide than it is today.

Putnam also invites quibbles by choosing families drawn from extremes to illustrate his case, especially among the poor. They include a girl being raised by her sister after their mother, a prostitute, died, possibly of AIDS; a homeless teenager with nine half-siblings and a father in prison; and a boy raised in the New Orleans projects who committed arson at 13 and who boasts, “I just love beating up somebody.” The rich kids mostly have model dads and Tiger Moms.

The poor families he profiles lead heartbreaking lives, but for most the troubles seem to date back generations. The recent growth of inequality, which began in the 1970s, would be glimpsed better a few rungs up the ladder, among the besieged working class. Oddly in a book about inequality we never learn how much money any of the families have.

Though Putnam is a political scientist, his account is politics-free. He bemoans low turnout among poor voters, but says nothing about new laws that make it harder to vote. He rues the difficulties of a father who earns the minimum wage, with no mention of the opposition to raising it. He criticizes proprietary schools that crank out worthless diplomas, but not the political spending that protects them.

The discussion doesn’t need partisan spin; some Democrats protect moneyed interests, too. But it’s impossible to understand inequality without understanding the power it gives those at the top to pull up the ladder. Perhaps Putnam’s see-no-politics approach is a wily strategy for reaching the broadest audience. Perhaps it’s just who he is.

His policy suggestions include expanded tax credits for the poor, greater access to quality day care and more money for community colleges. Does this agenda sound familiar? When President Obama proposed it in January, critics on the right said he was waging “class warfare.”

Toward the end of “Our Kids,” Putnam offers a brave confession: Before starting the project, he didn’t understand how hard it had gotten for poor kids to get ahead. He had risen from modest means. Therefore, he writes, “I assumed, so could kids from modest backgrounds today.” Now “I know better.”

It’s alarming to think that the class gaps have widened so quickly, even someone as eminent as Putnam lost track. To his credit, he was moved by the people he met — their intelligence, their resilience, their sheer likability. One downside to a society with a meritocratic gloss is that it encourages the winners to think that life is fairer than it is, to overlook the merit in those left behind. That’s something to talk about at the next family dinner.