Well, we don't actually know this do we? We know that it's very hard, and that it's never been done before, but so was running a sub-4 mile for most of human history.
If we knew the mechanism through which people learn perfect pitch and could prove that it vanishes with age, then you'd have an argument. But we're not there yet.
We don't know the mechanism, but we have hints. Surprisingly enough, relative pitch is the one most unique to humans. Birds have perfect pitch, and can fail to recognize a song if it's pitch-shifted by even a small amount. And we know what the signals are that come off of the cochlea (and we can even emulate them with a cochlear implant). So what's different is something in the way the brain processes the sounds, and to my knowledge, out of the millions of highly trained musicians there are in this world, none of them has developed perfect pitch outside of childhood.
> Birds have perfect pitch, and can fail to recognize a song if it's pitch-shifted by even a small amount
I have a pet parrot who seems to always sing in the same key. Now I feel bad for whistling off-key to him all these years!
Assuming that perfect pitch is an immutable skill after a certain point, I wonder whether the age of acquisition still matters. Do people who learn the skill earlier have more fine-grained perception?
Right, it rings too much like "You can't teach Chinese." It's more likely a combination of it being really difficult past childhood to begin with, and also that we haven't figured out how to teach it yet.
From personal experience, long ago I spent some time trying to acquire perfect pitch using a synesthetic method from somewhere, and eventually convinced myself that I was making some progress, but that the effort required to take it to the point of being at all useful wasn't going to be worth my practice time.
Well, we don't actually know this do we? We know that it's very hard, and that it's never been done before, but so was running a sub-4 mile for most of human history.
If we knew the mechanism through which people learn perfect pitch and could prove that it vanishes with age, then you'd have an argument. But we're not there yet.