Keolu should post the link rather than continue to lie....  these studies compare headstart preschool programs with other "broadbased" preschool programs.  Conclusion: they're all good. 

He lies that those who do NOT get these programs do not NEED them. Many do who lack the brain stimulation at home where their mothers lack the time to care for them and her friends who sleep during the day just wake up to feed and clean the kids in the crib. Mother comes home and is too tired to care for them and no siblings to play with.

These are the kids who get further and further behind in school and wind up being teen age mothers, unemployed, in prison, or on welfare. If we screen for these kids and provide for their preschool needs, the programs pays for itself in terms of future social costs, and the loss of the benefits of their work and jobs.