When Newsweek recently asked 1,000 U. S. citizens to take America’s official citizenship test, 29 percent couldn’t name the vice president. Seventy-three percent couldn’t correctly say why we fought the Cold War. Forty-four percent were unable to define the Bill of Rights. And 6 percent couldn’t even circle Independence Day on a calendar.

Don’t get us wrong: civic ignorance is nothing new. For as long as they’ve existed, Americans have been misunderstanding checks and balances and misidentifying their senators. And they’ve been lamenting the ignorance of their peers ever since pollsters started publishing these dispiriting surveys back in Harry Truman’s day. According to a study by Michael X. Delli Carpini, dean of the Annenberg School for Communication, the yearly shifts in civic knowledge since World War II have averaged out to "slightly under 1 percent. "

But the world has changed. And unfortunately, it’s becoming more and more inhospitable to incurious know-nothings—like us. To appreciate the risks involved, it’s important to understand where American ignorance comes from. In March 2009, the European Journal of Communication asked citizens of Britain, Denmark, Finland, and the U.S. to answer questions on international affairs. The Europeans outdid us. It was only the latest in a series of polls that have shown us lagging behind our First World peers.

Most experts agree that the relative complexity of the U. S. political system makes it hard for Americans to keep up. In many European countries, parliaments have proportional representation, and the majority party rules without having to "share power with a lot of subnational governments," notes Yale political scientist Jacob Hacker. In contrast, we’re saddled with a nonproportional Senate; a tangle of state, local, and federal bureaucracies; and near-constant elections for every imaginable office (judge, sheriff, school-board member, and so on). "Nobody is competent to understand it all, which you realize every time you vote," says Michael Schudson, author of The Good Citizen. "You know you’re going to come up short, and that discourages you from learning more. "

It doesn’t help that the United States has one of the highest levels of income inequality in the developed world, with the top 400 households raking in more money than the bottom 60 percent combined. As Dalton Conley, an NYU sociologist, explains, "it’s like comparing apples and oranges. Unlike Denmark, we have a lot of very poor people without access to good education, and a huge immigrant population that doesn’t even speak English. " When surveys focus on well-off, native-born respondents, the U. S. actually holds its own against Europe.

For more than two centuries, Americans have gotten away with not knowing much about the world around them. But times have changed—and they’ve changed in ways that make civic ignorance a big problem going forward. We suffer from a lack of information rather than a lack of ability. Whether that’s a treatable affliction or a terminal illness remains to be seen. But now’s the time to start searching for a cure.

Back in Truman’s day, Americans（）

A. were well aware of what was going on around them

B. already showed much ignorance about public affairs

C. did not know as much about civil rights as they do now

D. lamented the ignorance of the pollsters involved in surveys