Meditating on my conversation with paulfchristiano below, I realize that our intuitive conception of intelligence is probably not coherent. The following is quite a controversial point, but I think a lot of what counts as intelligence was under sexual selection.
This paper shows how the best explanation for the genetic variance underlying intelligence is mutation-selection balance, instead of selective neutrality or balancing selection. Traits under mutation selection balance have high mutational target size, i.e. rare mutations of significant effect all over the genome affect their expression. This makes such a trait a very good fitness indicator, as it tells you the mutation load of an individual. Hence if you see an intelligent person, you can be reasonably certain that the person has fewer deleterious mutations. Physical beauty is another such fitness indicator.
Now, using physical beauty as an analogy, let’s say the symmetry of the face correlates with genetic quality. Then it will become a fitness indicator, as the opposite sex benefits from knowing the genetic quality of potential mates. This they experience as ‘beauty’. Now, symmetry of breasts also happen to correlate with genetic quality. How does natural selection make them appreciate this? Why since we already have a conception of beauty why not go with that? So facial and breast symmetry both fall under ‘beauty’ even though phenotypically they don’t really have much to do with each other. For one, they serve very different functions.
We should expect the same for our intuitive appraisal of the intelligence of others. Diverse mental tasks having no intrinsic relation to one another, happen to correlate with genetic quality, hence natural selection makes us perceive their aggregate as ‘intelligence’.
Diverse mental tasks having no intrinsic relation to one another, happen to correlate with genetic quality, hence natural selection makes us perceive their aggregate as ‘intelligence’.
Hmm, doesn’t your theory predict that we should file these traits under ‘beauty’ instead?
Meditating on my conversation with paulfchristiano below, I realize that our intuitive conception of intelligence is probably not coherent. The following is quite a controversial point, but I think a lot of what counts as intelligence was under sexual selection.
This paper shows how the best explanation for the genetic variance underlying intelligence is mutation-selection balance, instead of selective neutrality or balancing selection. Traits under mutation selection balance have high mutational target size, i.e. rare mutations of significant effect all over the genome affect their expression. This makes such a trait a very good fitness indicator, as it tells you the mutation load of an individual. Hence if you see an intelligent person, you can be reasonably certain that the person has fewer deleterious mutations. Physical beauty is another such fitness indicator.
Now, using physical beauty as an analogy, let’s say the symmetry of the face correlates with genetic quality. Then it will become a fitness indicator, as the opposite sex benefits from knowing the genetic quality of potential mates. This they experience as ‘beauty’. Now, symmetry of breasts also happen to correlate with genetic quality. How does natural selection make them appreciate this? Why since we already have a conception of beauty why not go with that? So facial and breast symmetry both fall under ‘beauty’ even though phenotypically they don’t really have much to do with each other. For one, they serve very different functions.
We should expect the same for our intuitive appraisal of the intelligence of others. Diverse mental tasks having no intrinsic relation to one another, happen to correlate with genetic quality, hence natural selection makes us perceive their aggregate as ‘intelligence’.
Buyer beware!
Hmm, doesn’t your theory predict that we should file these traits under ‘beauty’ instead?