Your child may be at a disadvantage if he hasn't had any school experience before kindergarten. "In 1960, only 10 percent of 3- and 4-year-olds were enrolled in any type of classroom," says W. Steven Barnett, Ph.D., director of the National Institute for Early Education Research (NIEER), in New Brunswick, New Jersey. "But now nearly half of 3-year-olds and 70 percent of 4-year-olds are in some kind of program." Although this trend may reflect the rise in working moms, it's mostly due to the recognition that preschool provides a strong foundation for learning. That's not to say that a child from a loving home who has stimulation and social opportunities won't do well. But preschool teaches kids to be independent, to share, and to follow directions -- crucial skills for kindergarten.