Preschools help children prepare for the rigors of grade school—especially children who come from a minority family, a poor family, or whose parents don't provide high-quality interactions. The results of a new study of over 1,000 identical and fraternal twins, published in Psychological Science, a journal of the Association for Psychological Science, confirm that preschool programs are a good idea.
Of course, many children from poor families excel in school. But it's no secret that many do not. People used to think this had to do with the lower-quality schools in poor neighborhoods, but it has become clear that many poor children start first day of kindergarten playing catch-up. They score lower on tests that measure the kinds of skills that are foundational for learning mathematics and reading.
Elliot Tucker-Drob, of the University of Texas at Austin, used a study of 1,200 twins from 600 families to examine how their environment affects their achievement later. The goal of twin studies is to figure out how much of a particular trait is influenced by genetics and how much is influenced by the environment. If identical twins are more similar to each other than fraternal twins, it's because genes have some influence on the trait—in this case, test scores. If fraternal twins are also quite similar, that suggests that the trait is influenced by the family environment—how their parents play with them, for example. In this study, twins were followed from age 2 until they entered kindergarten at age 5.
Tucker-Drob found that children who went to preschool did better than children who did not, and that the family environment was important. Preschools were particularly beneficial for minority children and poor children, and for children whose parents didn't play with them in a way that stimulated the child's cognitive development. Parents' play styles were measured by having trained coders watch a videotape of a parent playing with each child. "This indicates that children who are growing up in homes that have fewer resources and lower-quality stimulation from parents aren't being held back as much by their homes if they're attending preschool," Tucker-Drob says.
For kids from wealthier backgrounds, with more stimulating environments, there was no difference between children who went to preschool and those who didn't. "But for children who came from poorer backgrounds, test scores were a lot higher if they went to preschool than if they stayed home," Tucker-Drob says. That means that, on average, preschools help children from disadvantaged backgrounds. The gap in test scores between rich and poor was much smaller among children who went to preschool than among children who did not. Tucker-Drob emphasizes that these are average effects; many children will thrive no matter the environment. "It's in no way saying that poor parents are bad; it's simply saying that there are these associations, and, potentially, one way to break this cycle is with preschools."