William, I am not disagreeing that genetics may play a dominant role, but I do think it is a very weak argument to compare chess playing aptitude to running. From what I have read, we know a great deal about what physical traits (fast twitch muscles, bone length ratios, and so forth) make someone a fast runner. We know a fair bit about the role genes play in developing these traits.
With chess-playing aptitude we have indirect evidence of genetics gathered statistically. Can we measure a trait like seratonin to dopamine ratios? Can we measure a physical trait like the size of the brain or the pattern of the folds of the neocortex and statistically associate it with chess aptitude? Not to my knowledge.
So while there may be a statistical and indirect argument to make about chess aptitude and genetics, I think it should be made as such rather than making an argument comparing chess aptitude to something like running where (at this time) we know a lot more about the direct traits involved.
Yes, I agree with you. I was reacting to the common attitude illustrated by the parent post that goes "Why does any group of people excel at something? It's necessarily because of culture and social support and you're stupid for considering anything else."
Postulating variations in the human brain is socially off the table, and perhaps this is the best way for it to be. The evidence people are willing accept as absolute proof that human brains are basically equal is weaker by several orders of magnitude than that which would convince them that there is any statistical difference in the brains of any populations.
One indication of this is that people who think that there is no significant statical pattern in variations of human brains never take that thought further toward interesting scientific questions. (For example, why have all groups of humans had the exact same evolutionary pressures on all kinds of intelligence, or why is intelligence seemingly unable to evolve in different directions, given that however you measure it it seems highly, highly heritable as shown by twin studies and other evidence?)
So basically, I'm just a mood to explore really politically incorrect and dangerous ideas, many of which may also be wrong. However, people who explore these ideas are not stupid, and reactions like "duh, it's the society" aren't really warranted. It may be socially irresponsible to think about ideas like this, and I'm agnostic about whether that's so. It quite possibly could be indicative of a very poor political sensibility too (see James Watson, Larry Summers.)
With chess-playing aptitude we have indirect evidence of genetics gathered statistically. Can we measure a trait like seratonin to dopamine ratios? Can we measure a physical trait like the size of the brain or the pattern of the folds of the neocortex and statistically associate it with chess aptitude? Not to my knowledge.
So while there may be a statistical and indirect argument to make about chess aptitude and genetics, I think it should be made as such rather than making an argument comparing chess aptitude to something like running where (at this time) we know a lot more about the direct traits involved.