The modern family is a lot different than it used to be. REUTERS/Mario Anzuoni

Picture the typical American family: what do you see? You probably imagine a married mom and dad with a couple of kids -- think the Draper family, circa Season 1 of Mad Men. You probably know that that ideal has held true for fewer and fewer families over the decades. But new data from the Pew Research Center shows that fewer than half of American kids now grow up in one of these "traditional" families.

Pew Research Center

As of 2013, only 46 percent of U.S. kids live in a traditional family structure of two parents in their first marriage. An additional 15 percent live with a parent who has been remarried at least once, 34 percent live with a single parent, and 5 percent have no parent at home -- this latter group is most likely living with a grandparent, according to Pew. By contrast, 73 percent of American kids lived with a traditional family back in 1960.

Looking at the chart, it's clear that the change is less a function of remarriages, and more due to the sharp rise in single parenting. As Emily Badger wrote last week, 41 percent of births these days are to unmarried mothers. Among black mothers, that figure rises to an astonishing 72 percent.

Researchers are in general agreement that children of unmarried parents tend to have a tougher time in life: more poverty, more instability, and more problems at school, among other things. But it's less clear what type of policy measures we might take to address these issues. As Emily noted, it doesn't make a whole lot of sense to encourage mothers to stay in relationships that may be abusive or otherwise more harmful to their children's health than going it alone.

But it's clear that the American family has changed dramatically over the past 50 years, and will likely continue to evolve. If policymakers of any political stripe want to help American families succeed, the first step is coming to grips with what that dramatic change looks like. For the majority of U.S. children, the traditional nuclear family is an ideal that doesn't reflect reality.