An interesting op-ed at the Wall Street Journal. (Via Instapundit.) A few key points:
A 2006 analysis by Education Week found that Oklahoma and Georgia were among the 10 states that had made the least progress on NAEP. Oklahoma, in fact, lost ground after it embraced universal preschool: In 1992 its fourth and eighth graders tested one point above the national average in math. Now they are several points below. Ditto for reading. Georgia’s universal preschool program has made virtually no difference to its fourth-grade reading scores. And a study of Tennessee’s preschool program released just this week by the nonpartisan Strategic Research Group found no statistical difference in the performance of preschool versus nonpreschool kids on any subject after the first grade.
What about Head Start, the 40-year-old, federal preschool program for low-income kids? Studies by the Department of Health and Human Services have repeatedly found that although Head Start kids post initial gains on IQ and other cognitive measures, in later years they become indistinguishable from non-Head Start kids. . .
If anything, preschool may do lasting damage to many children. A 2005 analysis by researchers at Stanford University and the University of California, Berkeley, found that kindergartners with 15 or more hours of preschool every week were less motivated and more aggressive in class. Likewise, Canada’s C.D. Howe Institute found a higher incidence of anxiety, hyperactivity and poor social skills among kids in Quebec after universal preschool.
The only preschool programs that seem to do more good than harm are very intense interventions targeted toward severely disadvantaged kids. . .
There’s a political angle too: Barack Obama seems to be making some insupportable claims about pre-school benefits.