ORIGINAL: ChickenOfTheSea
If human intelligence was due to the accumulation of a large number of small genetic effects, then we would be better able to explain it with reductionist thinking (as the molecular biologists want to do) and it would be susceptible to change by truncation selection (killing off the smartest or the dumbest).
However, human brain size and intelligence changed extremely rapidly in early humans whose interbreeding populations were very small so that stochastic effects play a more important role in genetics. Then it is more likely to involve the sort of changes described by Sewall Wright's shifting balance theory of evolution. From this standpoint human intelligence can be viewed as an emergent property not just functionally, but genetically as well. Reductionist arguments aren't nearly enough.
Complex traits that appear in this fashion have large amounts of non-additive genetic effects and the genetic variability is quite resistant to change by truncation selection. For this reason, eugenics was not only morally reprehensible but doomed to failure. Likewise, the practice of tyrants for millenia of killing the "smart" members of a subjugated population in order to breed a population of slaves is also pointless. The underlying genetic variation in intelligence now is probably the same as for the ancient Greeks. The genetics of intelligence involves potential intelligence and Herwin pointed out some important ways that environment affects realized intelligence.
Human intelligence, for better or worse, is what it is and has been for a long time.
That’s really interesting COTS. I’ve always been comfy with truncation because it’s logical. But I’m a physical sciences person, best I ever did in Bio was find the frog spleen, so what do I know.
But I’ve always been fascinated with the idea of intelligence as applied to ‘simulated’ or ‘artificial’ intelligence. A decision model can be as complete and complex as your processing power can make it, but when you’re done, what you got is structurally rational, self-consistent, and deterministic.
Warfare (avoiding the philosophy) is inherently irrational and inconsistent, and it seems to respond to intelligence in the human contextualization of the term. AI decision models can apparently provide a reasonable basis for infrastructure support and ‘laying out the Smorgasbord’, so to speak, but how often has ‘intelligence’ chosen the marginal option with breathtakingly successful results?
Can’t be reproducibly done with randomization, because ‘intelligence’ seems to provide a means to, somehow, accurately choose when and how to implement the odd option somewhere in the middle of the list. Why that option? Why that way?
Sigh … guess I’m not intelligent enuf to get there from here.
