The Benefits of Reading to Children, Tested With a Data Pool of One

One of the most controversial small points in Freakonomics was the claim that early childhood test scores are not correlated to the amount a child is read to at home.

If you read Carl Bialik‘s “Numbers Guy” column in today’s Wall Street Journal, you’ll learn why so many people have thought otherwise. Here’s an excerpt:

Children from low-income households average just 25 hours of shared reading time with their parents before starting school, compared with 1,000 to 1,700 hours for their counterparts from middle-income homes.

These oft-repeated numbers originate in a 1990 book by Marilyn Jager Adams titled, “Beginning to Read: Thinking And Learning About Print.” Ms. Adams got the 25-hours estimate from a study of 24 children in 22 low-income families. For the middle-income figures, she extrapolated from the experience of a single child: her then-4-year-old son, John …

These numbers have since been applied to all middle-income children. That’s akin to predicting that all young children from middle-income families will graduate college with a degree in psychology and statistics, as John, now 23, has done.