Not done Sir, but doing.

Plenty is doing.

"....data from three relevant adoption studies suggest that about half the relationship between environmental indices and IQ in non- adoptive homes is due to genetic similarity between parents and their children."

R.PLOMIN, 1987, in S. & Celia Modgil, Arthur Jensen: Consensus and Controversy. Brighton : Falmer.

Disclaimer: this quote appears here only to spark discussion. It is not endorsed one way or the other. Make up your own mind. Or just refresh the page for another viewpoint. From a collection assembled by the late Chris Brand.