Since its birth, the United States has always defined itself as an egalitarian meritocracy, fundamentally distinct from the class-ridden societies of Europe.

And at times, this has been true. On the eve of the country's Revolution, the income distribution of American colonists was far more equal than it was of those of Great Britain. “Indeed, New England and the Middle Colonies appear to have been more egalitarian than anywhere else in the measurable world,” wrote economic historians in a 2012 paper. (To be clear, it’s difficult to consider a slave-holding society egalitarian at all. It was brutally unequal. But from an income-distribution perspective, American colonists—meaning white men—were better off than their counterparts in Europe.)

Plenty has changed since then. The U.S. became increasingly unequal during the decades ahead of the Civil War in the 1860s. But at the dawn of the the 20th century, it was still more egalitarian than European nations like Britain and France. Inequality rose sharply during the Jazz Age and collapsed when the Great Depression hit, staying fairly stable until the early 1980s. Since then American inequality has climbed sharply—so much so that the U.S. is now more unequal than Europe was at the end of its aristocracy era and just before World War I, wrote French economist Thomas Piketty in his massive study on the topic, Capital in the Twenty-First Century.

Not only is the U.S. now less equal than Europe is, its population is also less mobile than those in many of the continent's countries. In the late 19th and early 20th centuries, Americans had a much easier time rising above the class into which they were born than did their counterparts in Britain, according to economic historian Joseph Ferrie. Now, a poor Moroccan kid in France is much more likely to move into the middle class than is a child born into a poor family in Mississippi. (The U.S. and Britain are said to have the lowest intergenerational social mobility among all European and North American countries. That means Americans' ultimate earnings are now heavily correlated with those of their parents. Here’s another study on the topic.)


Intergenerational Mobility by Country

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Few would argue that this is a healthy development. And almost all would agree that any change to this trend must be driven in part by the American education system. But here’s the catch: The American education system itself is actually an offshoot of an increasingly class-driven society.

Since the 1950s, American society has increasingly been segregated by socioeconomic status, with the percentage of the population considered middle-income steadily shrinking since 1970. The effects have clearly spilled over into schools.

“Relative to 40 years ago, high-income kids are more likely to be surrounded by other high-income kids, low-income kids by other low-income kids,” Greg Duncan, an academic who has studied the interaction of income segregation and equality, said in a speech earlier this year.

Such socioeconomic sorting causes all kinds of problems. Some are related to the schools themselves—so-called school effects—in that institutions that tend to serve poorer kids typically offer lower-quality, insufficiently financed education options. But other issues transpire when school systems are segregated by class, too. Since children of low-income parents typically are less prepared for high school and get less guidance when preparing for college, these kids can benefit immensely from going to school with with kids whose parents are college-educated and know the ropes a bit better. Both types of problems are important.n“But peer influences were far stronger than school effects,” said Gregory Palardy, who has studied the impact of socioeconomic segregation on high school achievement.

What's worse, the effects of socioeconomic and racial segregation linger even for the students who do manage to make it to college. These strivers graduate at far lower rates than their counterparts from more affluent families.

College Graduation Rates by Income Level

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Why? A number of universities and researchers speculate that a significant reason so many disadvantaged students fail to finish is that they feel that they don’t belong.

That’s not only a shame—it’s another indication of the socioeconomic chasms that keep Americans from different class backgrounds living in what are effectively different countries.

“I think the danger is that an unequal society can become a stratified society, and that inequality can begin to perpetuate itself almost automatically,” said Richard Reeves, policy director of the Center on Children and Families.

If the U.S. education system is any indication, that process is well underway.