I would say that most of the differences are cultural, not embedded in the DNA.
Children who do not receive adequate nutrition do not develop as well neurologically and end up less intelligent as a result. Thus, children born in poverty are disadvantaged.
A culture that places emphasis on avoiding “white” behavior (like getting good grades, succeeding at business, etc.) does not produce many highly intelligent individuals.
A culture that, conversely, places emphasis on working hard and trying to achieve more than anyone else produces a lot of intelligent and talented individuals.
I have heard about The Bell Curve, and do not dispute its premise. But the reasons for what it shows are complex.
“I would say that most of the differences are cultural, not embedded in the DNA.”
“The Bell Curve” takes into account cultural differences and the results don’t change much. It does a good job of eliminating as many variables as practically possible.
But regarding culture, when all is said and done, where do you think culture comes from if not from our genetic make up?
What constitutes culture are our most fundamental values.
Values are rules that we live by that we believe will serve us best in the long run. We come by those rules through the school of hard knocks called experience AND through having the intelligence and wisdom to learn those lessons. In other words to be “smart” enough to appreciate those lessons and to live by them.
“A culture that places emphasis on avoiding “white” behavior (like getting good grades, succeeding at business, etc.) does not produce many highly intelligent individuals.”
Again how did the people that practice that “culture” acquire that culture. Do you think those people “ON AVERAGE” were high IQ people or low IQ people? And by the way, not only do they place emphasis on avoiding “white” behavior, they also avoid “asian” behavior - see any correlation with average IQ there?
I would rephrase your sentence as follows.
“A culture that fails to appreciate behavior (rules of life) that works in the long term (like getting good grades, succeeding at business, etc.) is the product of low intelligent individuals.”
Which is statistically proven by the fact that IQ on average is highly correlated with success in life.
In other words, intelligence dictates culture more than the other way. Although there is a positive feedback mechanism as well (through humans selectively breeding) where culture can influence the group’s intelligence over the long run.