He's not calling for more study. He is saying the evidence from studies supports his belief.
Two things he didn't point out is that the left adamantly supports evolution without Divine intervention. Genetic selection is a requirement to pass on traits. Yet they can't accept the notion that behavior is in part due to the nature of the individual. To them differences are formed purely by nurture which is the opposite to evolution.
The religious right won't accept evolution which pretty much means nature is meaningless. There is no need to determine any cause and effect with traits. It's purely a spiritual notion, nurture. To them for the last 6,000 years we bear original sin no matter how we behave or to any lineage we belong.
I'm inclined to believe nature and nurture both form the basis of our behavior. I read this is what he believes. I suppose if you are inclined to cite this as BS then you fall in the category of the loony left or crazed creationist.
I have seen nurture beat nature. Friend of mine has a mother who was a major stoner, which resulted in a lot of my friend’s health problems. She went on to get a PhD in microbiology, is now teaching, has significant papers being referenced globally. All this in spite of stoner mommy.
Right James, whatever you say. The correlation sucks so you discount it. Good science!