Impact of pre-college schooling on IQ (WAIS)?
Almost a week with no answer. I found an article covering part of the topic, though. 



http://www.svt.ntnu.no/iso/torberg.falch/Articles/Article.pdf 

THE EFFECT OF EDUCATION ON COGNITIVE ABILITY

TORBERG FALCH and SOFIA SANDGREN MASSIH

Economic Inquiry. Vol. 49, No. 3, July 2011, 838–856