In the meantime, what children are reading doesn’t really matter—it’s better for them to acquire skills that will enable them to discover knowledge for themselves later on than for them to be given information directly, or so the thinking goes. That is, they need to spend their time “learning to read” before “reading to learn.” Science can wait; history, which is considered too abstract for young minds to grasp, must wait. Reading time is filled, instead, with a variety of short books and passages unconnected to one another except by the “comprehension skills” they’re meant to teach.

As far back as 1977, early-elementary teachers spent more than twice as much time on reading as on science and social studies combined. But since 2001, when the federal No Child Left Behind legislation made standardized reading and math scores the yardstick for measuring progress, the time devoted to both subjects has only grown. In turn, the amount of time spent on social studies and science has plummeted—especially in schools where test scores are low.

And yet, despite the enormous expenditure of time and resources on reading, American children haven’t become better readers. For the past 20 years, only about a third of students have scored at or above the “proficient” level on national tests. For low-income and minority kids, the picture is especially bleak: Their average test scores are far below those of their more affluent, largely white peers—a phenomenon usually referred to as the achievement gap. As this gap has grown wider, America’s standing in international literacy rankings, already mediocre, has fallen. “We seem to be declining as other systems improve,” a federal official who oversees the administration of such tests told Education Week.

All of which raises a disturbing question: What if the medicine we have been prescribing is only making matters worse, particularly for poor children? What if the best way to boost reading comprehension is not to drill kids on discrete skills but to teach them, as early as possible, the very things we’ve marginalized—including history, science, and other content that could build the knowledge and vocabulary they need to understand both written texts and the world around them?

In the late 1980s, two researchers in Wisconsin, Donna Recht and Lauren Leslie, designed an ingenious experiment to try to determine the extent to which a child’s reading comprehension depends on her prior knowledge of a topic. To this end, they constructed a miniature baseball field and peopled it with wooden baseball players. Then they brought in 64 seventh and eighth graders who had been tested both for their reading ability and their knowledge of baseball.

Recht and Leslie chose baseball because they figured lots of kids who weren’t great readers nevertheless knew a fair amount about the game. Each student was asked to first read a description of a fictional baseball inning and then move the wooden figures to reenact it. (For example: “Churniak swings and hits a slow bouncing ball toward the shortstop. Haley comes in, fields it, and throws to first, but too late. Churniak is on first with a single, Johnson stayed on third. The next batter is Whitcomb, the Cougars’ left-fielder.”)