Thanksgiving is perhaps the quintessential American family holiday, but what, exactly, does the quintessential American family look like today? Gay marriage laws have happily extended legal rights to same-sex couples, but over the last half century, a less auspicious family development has been the rise of single moms and dads and the decline of two-parent households, particularly among lower-income and less-educated families.

New Census numbers help tell the story:

The big takeaway here is that college graduates overwhelmingly raise children together (88 percent have a married spouse present). Non-college-grads are more than twice as likely to raise their child alone.

I took the Census figures and turned them into pie charts to accentuate the percentage difference in family arrangements by education. What you might call the "traditional" family structure (two parents raising their kids, together) dissipates as you move down the education ladder.

The blue slice represents what some people might consider a traditional family: Two married parents raising kids together.

Education and income go hand-in-hand, and so it will come as no surprise that richer individuals are more likely to married, regardless of race and education, and poorer individuals are much less likely to be married. This graph shows *all* Americans over the age of 15.

The point here isn't that marriage should be universal, or that we should abolish divorce, or that married two-parent households are the only possible way to properly raise a child. Rather, the big idea is that rich, educated people are more likely to marry, more likely to marry each other, and more likely to use their resources and the obvious time benefits of a two-parent household to produce educated (and rich) children. This is a virtuous cycle, and it turns vicious for the poor. Across the income spectrum, single parents have a tough time balancing work and child-rearing, especially when work earns them very little money. You don't have to be a cultural conservative to acknowledge that the disintegration of the traditional family structure at the bottom of our economic ladder means that too many kids have fallen behind before they set foot in school.

Being raised by both parents should not be a rich kid's exclusive privilege. And it isn't, yet: More than 60 percent of high-school dropouts still raise their children in two-parent households. But that figure is inching dangerously downward.