Educators and parents are obsessed with reading; and the emphasis has only grown in recent decades as reading became a defining indicator of academic success on standardized tests. Yet despite the obsession with teaching reading in the early grades, many educators don’t fully understand how the brain reads, writes Daniel Willingham, a professor of psychology at the University of Virginia, in a New York Times op-ed.

Willingham has long studied the best ways to teach reading and has noticed that factual knowledge often gets left out of the reading comprehension equation. Well-intentioned teachers help kids learn to decode words, but can’t understand why so many kids have trouble comprehending what they read. Willingham contends that lack of knowledge about the subject of the reading is a big culprit.

Kids are generally tested on reading comprehension as a separate skill, divorced from any subject they’ve learned about, and that favors kids who come to school with more prior knowledge — often wealthier kids. Willingham has some concrete ideas about how districts and schools can rethink reading curriculum to solve this problem:

Current education practices show that reading comprehension is misunderstood. It’s treated like a general skill that can be applied with equal success to all texts. Rather, comprehension is intimately intertwined with knowledge. That suggests three significant changes in schooling.

First, it points to decreasing the time spent on literacy instruction in early grades. Third-graders spend 56 percent of their time on literacy activities but 6 percent each on science and social studies. This disproportionate emphasis on literacy backfires in later grades, when children’s lack of subject matter knowledge impedes comprehension. Another positive step would be to use high-information texts in early elementary grades. Historically, they have been light in content.

Second, understanding the importance of knowledge to reading ought to make us think differently about year-end standardized tests. If a child has studied New Zealand, she ought to be good at reading and thinking about passages on New Zealand. Why test her reading with a passage about spiders, or the Titanic? If topics are random, the test weights knowledge learned outside the classroom — knowledge that wealthy children have greater opportunity to pick up.

Read the full New York Times op-ed below for that third suggestion.

Opinion | How to Get Your Mind to Read

Knowledge also provides context. For example, the literal meaning of last year’s celebrated fake-news headline, “Pope Francis Shocks World, Endorses Donald Trump for President,” is unambiguous – no gap-filling is needed. But the sentence carries a different implication if you know anything about the public (and private) positions of the men involved, or you’re aware that no pope has ever endorsed a presidential candidate.