Identical twin studies where the twins were implanted into different women's uteruses? Because if not, you aren't proving "determined by genetics"; you're possibly just showing effects of good/bad prenatal care.
So I guess I'm curious about your sources... you can find poorly-designed studies badly interpreted by news media to prove just about anything.
So I guess I'm curious about your sources... you can find poorly-designed studies badly interpreted by news media to prove just about anything.