Over the past few months, writers from Charles Murray to Timothy Noah have produced alarming work on the growing bifurcation of American society. Now the eminent Harvard political scientist Robert Putnam and his team are coming out with research that’s more horrifying.

While most studies look at inequality of outcomes among adults and help us understand how America is coming apart, Putnam’s group looked at inequality of opportunities among children. They help us understand what the country will look like in the decades ahead. The quick answer? More divided than ever.

Putnam’s data verifies what many of us have seen anecdotally, that the children of the more affluent and less affluent are raised in starkly different ways and have different opportunities. Decades ago, college-graduate parents and high-school-graduate parents invested similarly in their children. Recently, more affluent parents have invested much more in their children’s futures while less affluent parents have not.

They’ve invested more time. Over the past decades, college-educated parents have quadrupled the amount of time they spend reading “Goodnight Moon,” talking to their kids about their day and cheering them on from the sidelines. High-school-educated parents have increased child-care time, but only slightly.

A generation ago, working-class parents spent slightly more time with their kids than college-educated parents. Now college-educated parents spend an hour more every day. This attention gap is largest in the first three years of life when it is most important.

Affluent parents also invest more money in their children. Over the last 40 years upper-income parents have increased the amount they spend on their kids’ enrichment activities, like tutoring and extra curriculars, by $5,300 a year. The financially stressed lower classes have only been able to increase their investment by $480, adjusted for inflation.

As a result, behavior gaps are opening up. In 1972, kids from the bottom quartile of earners participated in roughly the same number of activities as kids from the top quartile. Today, it’s a chasm.

Richer kids are roughly twice as likely to play after-school sports. They are more than twice as likely to be the captains of their sports teams. They are much more likely to do nonsporting activities, like theater, yearbook and scouting. They are much more likely to attend religious services.

It’s not only that richer kids have become more active. Poorer kids have become more pessimistic and detached. Social trust has fallen among all income groups, but, between 1975 and 1995, it plummeted among the poorest third of young Americans and has remained low ever since. As Putnam writes in notes prepared for the Aspen Ideas Festival: “It’s perfectly understandable that kids from working-class backgrounds have become cynical and even paranoid, for virtually all our major social institutions have failed them — family, friends, church, school and community.” As a result, poorer kids are less likely to participate in voluntary service work that might give them a sense of purpose and responsibility. Their test scores are lagging. Their opportunities are more limited.

A long series of cultural, economic and social trends have merged to create this sad state of affairs. Traditional social norms were abandoned, meaning more children are born out of wedlock. Their single parents simply have less time and resources to prepare them for a more competitive world. Working-class jobs were decimated, meaning that many parents are too stressed to have the energy, time or money to devote to their children.

Affluent, intelligent people are now more likely to marry other energetic, intelligent people. They raise energetic, intelligent kids in self-segregated, cultural ghettoes where they know little about and have less influence upon people who do not share their blessings.

The political system directs more money to health care for the elderly while spending on child welfare slides.

Equal opportunity, once core to the nation’s identity, is now a tertiary concern. If America really wants to change that, if the country wants to take advantage of all its human capital rather than just the most privileged two-thirds of it, then people are going to have to make some pretty uncomfortable decisions.

Liberals are going to have to be willing to champion norms that say marriage should come before childrearing and be morally tough about it. Conservatives are going to have to be willing to accept tax increases or benefit cuts so that more can be spent on the earned-income tax credit and other programs that benefit the working class.

Political candidates will have to spend less time trying to exploit class divisions and more time trying to remedy them — less time calling their opponents out of touch elitists, and more time coming up with agendas that comprehensively address the problem. It’s politically tough to do that, but the alternative is national suicide.