Baloney.., including the control group there were about 300 kids in the study. There are few historical studies like this but that is what is needed? Actually there are numerous studies that show the same thing. Studies like this have established this effect about 60 years ago. Since they have verified numerous times, there is universal agreement by early educators now that preschool has a major effect.

In comparison the study you mention includes a lot of kids with good home environment so there is no control group with poor or no ed stimulation at home. All the studies show is that academically oriented prekindergarten programs don't have a lasting effect in the short term and in contrast the long term effects may be bad.