Just as people share similarities in physical features with their closest relatives, so too do they share more genes and DNA and the characteristics these influence. Whether you call it race, or nationality, or the founder effect, it is useful in genetic linkage and genetic counseling to know something about one's heritage. Just as the way we look can be largely influenced by genetics, so, too, can the way we think, our assorted talents, skills, abilities. Clearly this is more true in some people than others. Beethoven may have been born with a particularly abundant or plastic set of neurons that enabled his musical abilities...but had no one thought to give him access to a piano, he would not have been the Beethoven we know. The piano is environmental. But if we gave all kids pianos, we'd produce few prodigies like Beethoven. Kids with down syndrome look share physical and mental features caused entirely by a genetic duplication of the 21st chromosome. They score more similarly to eachother than to their non-affected siblings on growth, intelligence, skills attained, health, etc. Clearly, genes have a major impact on these results. Poor nutrition, head injuries, an unenriched environment or non responsive parenting can lead to similar test scores--in which case the environment is the greatest risk factor.
I would hope that we don't get so politically correct that we can't notice tendencies amongst groups or comment upon them. Asians tend to have straighter blacker coarser hair...and they also average higher test scores in math than those who don't identify themselves as Asian. Children born in Africa to native Africans tend to have dark skin and to walk a month earlier than children whose parents don't identify them as African. Men tend to be taller than women and are also more prone to committing acts of violence. Women tend to have larger breasts than men, and also tend to be more trusting or credulous (or gullible) than men. Yes, these are fuzzy categories...and just as there is a lot of overlap and examples that do not fit the norm--it doesn't mean that categorizing people isn't useful at times. And if DNA can cause people to look different on the outside...it can cause internal differences too from the breeding populations that produced the physical differences. If it's okay to say that small dogs are more likely to shake and be yippy and shepherd looking dogs are often easier to train for police work or agility training...then it should be okay to comment on tendencies involving fuzzy but recognizeable groups of people.
Americans tend to have a pretty good mix of both African and Asian genes (Asian from native Americans...African from Africa and the migration up towards Europe--the Asians came over first from the west and were latter dominated by the Europeans from the Northeast). You can see this mixing in blood types, but you can also see it when you observe differences between those who identify themselves as "black" and those who identify themselves as "Asian"-- wherever the scores vary--be it penis size or pattern recognition, Americans tend to fall in the middle.
So I weigh in on the side that fuzzy categories can be useful tools for understanding, but I would hate to see it used for divisiveness or prejudice. We are talking about tendencies amongst groups, and it cannot be applied to an individual and, as skeptical thinkers, I think we'd want to be especially careful about "confirmation bias". But I hope we don't let political correctness keep us from voicing observations and data about tendencies amongst groups of people.
