peer-reviewed research to support that, even though it is admittedly difficult to isolate genetics as an independent variable.
As for the last part, all those "blah-blah socio-economic" factors also play a significant role, by ANY measure. No rational person would argue they don't have a significant impact.
You make very great claims, then back them up with links to blog posts and books of dubious reputation. I need data! What are the sample sizes? What are the standard deviations? I'll keep my mind open. If you should find something a little more reliable, please do post it. For now however, I'm going to have to say your claims are unsubstantiated.