What Children Already Know Shapes What They Understand: The Role of Background Knowledge in Reading

We often think of reading comprehension as a skill children develop — something they get better at through practice. And that's true. But research reveals that comprehension depends just as much on what a child already knows as on how well they can decode words on a page.

What Researchers Found

Background knowledge — the information a reader brings to a text before they start reading — plays a central role in comprehension. A now-classic study by Recht and Leslie (1988) demonstrated this vividly: students who knew a lot about baseball understood a passage about a baseball game far better than students with stronger general reading ability but less baseball knowledge. The high-knowledge, weaker readers outperformed the low-knowledge, stronger readers.

This finding has been replicated and extended many times. Researcher E.D. Hirsch Jr. spent decades arguing, backed by cognitive science, that reading comprehension is not a transferable skill like riding a bike — it is deeply tied to domain knowledge. His work, along with research from cognitive scientists like Daniel Willingham, shows that the brain uses prior knowledge as a scaffold: when you already know something about a topic, you can connect new information to what you know, fill in gaps, make inferences, and remember more of what you read.

The IES Practice Guide Improving Reading Comprehension in Kindergarten Through 3rd Grade (U.S. Department of Education, 2010, updated 2023) recommends building content knowledge explicitly as a comprehension strategy — not just teaching comprehension skills in isolation, but ensuring children have rich exposure to science, history, geography, and the arts so they arrive at texts with something to work with.

Why It Matters

A child who can decode fluently but lacks background knowledge will still struggle with comprehension as texts grow more complex in the upper elementary grades and beyond. Building broad knowledge — about animals, weather, history, how things work — is not a distraction from literacy. It is literacy work.

What You Can Try

At home: Read and talk about a wide range of topics with your child — not just stories, but nonfiction books, nature documentaries, museum visits, and conversations about how the world works. Every new topic your child learns about becomes a comprehension asset the next time they encounter it in a text.

In the classroom: Before introducing a new reading unit, spend time building the relevant background knowledge explicitly. A brief video, a read-aloud of an accessible nonfiction text, or a class discussion about the topic primes students to understand and remember far more of what they read.

The knowledge children accumulate — about science, history, people, and places — is not separate from reading. It is the foundation reading comprehension is built on.

Sources

• Recht, D. R., & Leslie, L. — "Effect of Prior Knowledge on Good and Poor Readers' Memory of Text," Journal of Educational Psychology, 1988
• Willingham, D. T. — Why Don't Students Like School?, Jossey-Bass, 2009 (Chapter 2: background knowledge and reading comprehension)
• Hirsch, E. D. Jr. — The Knowledge Deficit, Houghton Mifflin, 2006
• Institute of Education Sciences — Improving Reading Comprehension in Kindergarten Through 3rd Grade (IES Practice Guide), U.S. Department of Education, 2010 (guidance updated 2023)