I agree wholeheartedly with the theme of your comments.
I do wonder, though, what is your source that genetics is not a contributing factor and, in particular, your source for the increased IQ since published by the Bell Curve almost 30 years ago (Polish vs. Germany, etc.).
Thomas Sowell, “New Light on Black I.Q.” New York Times Magazine, March 27, 1977, pp. 57ff
James R. Flynn, “Mean IQ of Americans: Massive Gains 1932 to 1978” Psychological Bulletin 95 (1984): 29-51.
“Massive IQ Gains in 14 Nations” Psychological Bulletin 101 (1987): 171-91.
Eka Roivainen,“Economic, educational, and IQ gains in eastern Germany 1990-2006” Intelligence 40 (2012): 571-75.
William T. Dickens & James R. Flynn, “Black Americans Reduce the Racial IQ Gap: Evidence from Standardization Samples” Psychological Science, October 2006.