Giving children access to print materials is associated with positive behavioral, educational and psychological outcomes. (“Access to Print Materials Improves Children’s Reading,” study commissioned by Reading is Fundamental, 2010.
The only behavior measure that correlates significantly with reading scores is the number of books in the home. (Jeff McQuillan, “The Literacy Crisis: False Claims, Real Solutions,” 1998.)
Children growing up in homes with lots of books are on average three years ahead academically. (M.D.R. Evans et al, “Family scholarly culture and educational success: Books and schooling in 27 nations,” Research in Social Stratification and Mobility, June 2010)