Oh my, I have seldomly been accused of creationism. To be clear, I can separate the ability from the creature. I don't have a religious or otherwise attachment to the human form specifically. Other than - to be completely honest here - being one.
Let's just clear that out of the way. What I am "claiming", which would be an exaggeration because I'm sort of exploring here, is that whatever human cognition is may be an optimal or near-optimal state of cognitive ability.
So, to be fair, give Koko some millions of years and some evolutionary pressure and I'm sure she'll join us and I'd be happy to have her on our team.
Your point about our ability to hold our breath and how it lead to our increasing dominance is fascinating. I have to say I am not completely sold on the idea that holding your breath is the only way to develop proper channels of communication for I can easily imagine some sort of physical signaling standing in for at least parts of it. That said, I can appreciate the immediate and overwhelming advantage of speech.
This does stimulate my curiosity about what came first here, speech or cognitive ability? Why did "we" even consider speaking? How does one do that without having the cognitive architecture for recognizing its value in the first place? In other words, was "us" being smarter the catalyst for speaking or was it the other way around? Fascinating and I am way too much of an amateur to say anything more of value on it.
I will however continue do so anyway, because that is my sacred duty as a dedicated HN'er and allround developer douchebag.
> What can be more uncommon than living on a trees without a warm house and typically without any house at all, without regular nutrition, with a lot of really different enemies from tiny insects to giant cats, with a regular fights, with no democracy and law and medicine?
I might be in danger of being too blunt here, but this is the bar you have to clear if you wish to survive. This is exactly what humans are capable of even in their "undeveloped" form. These sort of pressures might be foundational to our evolution, but then again, every animal has to deal with it in some way or another so I'm not sure what made us take what I can only call the excessively cerebral path. Maybe it was like the evolution of the peacock's tail? A runaway process, leading to miraculous but exorbitant results like the mantis shrimp's eyes.
What I mean by uncommon is: can we coach you to pick cotton, whittle little wooden sculptures, play a game like checkers and sing simple songs or whatever else is appropiate for your particular physical form and has virtually no bearing on your immediate survival? I know this is a hard thing to pin down, because one can come up with myriad examples of varying levels of persuasive power but you surely perceive some differences here even if they are hard to lock into? Differences that cannot just be attributed to language or lack of proper motivation.
It's not so much every thing we can do in particular that's piquing my interest, but the sheer breadth of things we are capable of taking on both physical (parkour, gymnasts) and cerebral (chess, math). I didn't even get to art, which is like a whole world on its own and the various combinations of all those domains.