One of America’s leading political scientists, Robert Putnam, has just come out with a book called “Our Kids” about the growing chasm between those who live in college-educated America and those who live in high-school-educated America. It’s got a definitive collection of data about this divide.

Roughly 10 percent of the children born to college grads grow up in single-parent households. Nearly 70 percent of children born to high school grads do. There are a bunch of charts that look like open scissors. In the 1960s or 1970s, college-educated and noncollege-educated families behaved roughly the same. But since then, behavior patterns have ever more sharply diverged. High-school-educated parents dine with their children less than college-educated parents, read to them less, talk to them less, take them to church less, encourage them less and spend less time engaging in developmental activity.

Interspersed with these statistics, Putnam and his research team profile some of the representative figures from each social class. The profiles from high-school-educated America are familiar but horrific.

David’s mother was basically absent. “All her boyfriends have been nuts,” he said. “I never really got to see my mom that much.” His dad dropped out of school, dated several woman with drug problems and is now in prison. David went to seven different elementary schools. He ended up under house arrest, got a girl pregnant before she left him for a drug addict.