Does preschool matter? Yes, tremendously — for children from “poor” homes:
The gift of preschool, then, is that closes the yawning gap between the life experiences of wealthy and poor toddlers, thus making whatever differences remain more important.
This effect was clearly demonstrated by the standardized test data, as Tucker-Drob looked at changes in scores correlated with preschool. Not surprisingly, he found that preschool significantly closed the achievement gap between rich and poor kids. However, this winnowing of the gap was entirely due to the raised scores among those from disadvantaged homes. In fact, Tucker-Drob found that children raised in wealthier homes got no benefit at all from pre-k education, as their test scores remained flat. Because these kids were already receiving plenty of cognitive stimulation at home, it didn’t really matter if they were also stimulated at school. It’s as if their brains were already maxed out.
This latest study builds on previous work by Tucker-Drob showing that the impact of parents, at least relative to genetics, largely depends on socioeconomic status. Last year, he looked at 750 pairs of American twins who were given a test of mental ability at the age of 10 months and then again at the age of 2. As in this latest study, Tucker-Drob used twin data to tease apart the importance of nature and nurture at various points along the socioeconomic continuum. The first thing he found is that, when it came to the mental ability of 10-month-olds, the home environment was the key variable, across every socioeconomic class. This shouldn’t be too surprising: Most babies are housebound, their lives dictated by the choices of their parents.
Results for the 2-year-olds, however, were dramatically different. In children from poorer households, the decisions of parents still mattered. In fact, the researchers estimated that the home environment accounted for approximately 80 percent of the individual variance in mental ability among poor 2-year-olds. The effect of genetics was negligible.
The opposite pattern appeared in 2-year-olds from wealthy households. For these kids, genetics primarily determined performance, accounting for 50 percent of all variation in mental ability.