So some of this early years shit the government's going on about is actually based on evidence

Here's one paper I've come across this evening which shows the
possibility for enriched environemnts for 3-5 year olds helping in later
life.

Effects of Environmental Enrichment at Ages 3-5 Years on Schizotypal
Personality and Antisocial Behavior at Ages 17 and 23 Years -- Raine et
al. 160 (9): 1627 -- Am J Psychiatry (abstract only)
<http://ajp.psychiatryonline.org/cgi/content/abstract/160/9/1627>
"
Effects of Environmental Enrichment at Ages 3–5 Years on Schizotypal
Personality and Antisocial Behavior at Ages 17 and 23 Years
Adrian Raine, D.Phil., Kjetil Mellingen, M.A., Jianghong Liu, Ph.D.,
Peter Venables, Ph.D., and Sarnoff A. Mednick, D.Med.

OBJECTIVE: Methods to prevent two major mental disorders, schizophrenia
and conduct disorder, have been elusive. This study assessed the effects
of an early nutritional, educational, and physical exercise enrichment
program on adult outcome for schizotypal personality, conduct disorder,
and criminal behavior. METHOD: Eighty-three children were assigned to an
experimental enrichment program from ages 3 to 5 years and matched on
temperament, nutritional, cognitive, autonomic, and demographic
variables with 355 children who experienced usual community conditions
(control group). Both self-report and objective measures of schizotypal
personality and antisocial behavior were obtained when the subjects were
ages 17 and 23 years. RESULTS: Subjects who participated in the
enrichment program at ages 3–5 years had lower scores for schizotypal
personality and antisocial behavior at age 17 years and for criminal
behavior at age 23 years, compared with the control subjects. The
beneficial effects of the intervention were greater for children who
showed signs of malnutrition at age 3 years, particularly with respect
to outcomes for schizotypy at ages 17 and 23 and for antisocial behavior
at age 17. CONCLUSIONS: The results are consistent with an increasing
body of knowledge that implicates an enriched, stimulating environment
in beneficial psychological and behavioral outcomes. These findings have
potential implications for the prevention of schizophrenia and criminal
behavior.
"