The rich aren't rich because they work harder. (Paul Sakuma/AP Photo)

America's long held infatuation with hard work might be eating into its understanding of inequality.

A quarter of the country believes the most important reason inequality exists is that some people (ahem, the rich) work harder than other people (the poor), according to a new report by the Pew Research Center.

The proportion of Americans who blame the underprivileged's work ethic for inequality is surprising because it's unusual. Of the 44 countries included in Pew's survey, only two —England and Uganda — were equally as unimpressed with the poor's working habits, and only Nicaragua was found to have a greater percentage of people (31 percentage) who hold that view. In Germany, Israel, and Italy, by comparison, only 10 percent, 7 percent, and 3 percent of the population, respectively, said the main reason an income gap persists is because some people work harder than others.

And worldwide, only 10 percent of people blamed effort for the inequality.

Why so many Americans think the poor simply aren't working hard enough is unclear.

It's not because they're working less, or inflexible about their work hours, as my colleague Matt O'Brien pointed out earlier this week. It's quite the opposite, actually: "Weekends, he explained, "are a luxury the bottom 30 percent can't afford."

The opinion also overlooks the fact that the country's top earners are getting richer faster than anyone else — and at a rate which is globally exceptional.

"This skewing of pay at the very top in the United States contrasts with other countries," says a new paper published by the National Bureau of Economic Research. It's hard to see how that rising earning power could simply be explained by increased dedication or hard work, especially when wages are soaring at the top and remaining stagnant most everywhere else, and certainly at the bottom.

One possibility is that many Americans misperceive the reasons for inequality because they misperceive just how big the gap is in the first place. A recent study at Harvard Business School found that Americans wildly underestimate the country's CEO-worker pay gap. And an exceptionally small portion of the country (only 13 percent) feels that worker pay is the main culprit behind inequality — the fifth lowest percentage Pew observed in the study, and well below the worldwide average of 19 percent. Misunderstanding the size of the gap might lead some to see it as being caused less by structure and more by behavior.

Another possibility is that many Americans hold the opinion because it jibes with notion that the United States is still a land of opportunity. Americans, after all, aren't as quick to blame their government for the gap as people are elsewhere. Only 24 percent of the country believes economic policies are the most important reason for inequality, which is well below the median among all advanced economies Pew polled (32 percent), the median globally (29 percent), and Greece and Spain, where roughly half of the population says inequality is the government's fault.

And all of this is made stranger by the reality that most Americans (nearly 70 percent) believe the government should do a lot (or at least something) to help reduce the gap.