Ah, the old nature versus nurture thing. Well, I believe in the nurture philosophy. Nature does play a role but nurture does determine what the person does and becomes.
That reminded me of study that was being talked about some years ago. It turns out that children of wealthy blacks tend to perform poorly compared to white students who come from families with average socioeconomic status. If it is caused by nurture you have to wonder what is being done wrong.
I think one of the most striking studies was Bouchard's study of identical twins which showed that nature has a very profound effect of personality: Like the prior, smaller studies of monozygotic twins reared apart, about 70% of the variance in IQ was found to be associated with genetic variation. On multiple measures of personality and temperament, occupational and leisure-time interests, and social attitudes, monozygotic twins reared apart are about as similar as are monozygotic twins reared together. These findings extend and support those from numerous other twin, family, and adoption studies. It is a plausible hypothesis that genetic differences affect psychological differences largely indirectly, by influencing the effective environment of the developing child. This evidence for the strong heritability of most psychological traits, sensibly construed, does not detract from the value or importance of parenting, education
This study compares genetically identical people raised in different environments. Alternately, many parents have noticed very different personalities in non-identical siblings raised in the same environment.
Extreme environment differences can have a big effect on personality, however. I think there was an example of a pair of separated twins in Germany in the thirties. One joined the Hitler youth, the other became a Rabbi. I wonder if they ever met later in life.
But the point I have been trying to make is that the social environment is affected by personalities and vice versa, mating trends are affected by personalities and social environment and genetics affect personalities. All this positive feedback is what creates races and cultures.