That's because debating you when the issue is science is like talking to a wall. I gave you a link to a critique of the Abecedarian Early Intervention Project study which demonstrated that the intervention cohort was stacked. Here, I'll quote it directly:
Originally Posted by AdamT
Four cohorts were recruited over a 5-year period, but the experimental group in Cohorts 3 and 4 produced unusually high scores on the Bayley MDI. Differences between experimental and control groups at 60 months of age were comparable to differences at 6 months of age.
What you're seeing at age 21 was also seen at ages 5 and 12 and also at the beginning of the study.
Let's toss this around for a bit. For the sake of this discussion I'll pretend that what you want to be true is indeed true. OK, let's say that early intervention works. Let's also pretend that this study wasn't focused on borderline retarded children but children in the normal cognitive range.
The bottom line is that they effectively proved that intensive, high-qualit child care from infancy can and does improve cognitive ability and it also has a number of quantifiable benefits
Here's my question to you - If Early Childhood Education effectively improves outcomes during childhood and those outcomes are stable into adulthood, then what? Tell me what you propose if this magic world could be brought about. Give me your policy wishlist.