Natural/supernatural isn't the same distinction as material/mental...
"Dualism" refers to ontologies with two distinct types of substances or realms. In Cartesian Dualism, mental states dwell exclusively in the supernatural half.
So the potential scarcity of dualism or prevalence of monism among adults and cultural norms of some societies doesn't necessarily change anything.
It's not about scarcity. It's that being either dualist or monist is not an inherent cognitive structure (like interpreting the world in 3 physical dimensions, or enhanced facial recognition skills). They're socially constructed beliefs.
Infants do develop some vague concept of their self at some point, do they not?
Sure. But that doesn't mean that all humans are dualist by default.
There's credible evidence that among American children (from diverse ethnic and socioeconomic backgrounds) aged 4-6 there's a strong tendency to suppose that the mental states of an anthropomorphized mouse eaten by an alligator in puppet show would continue....
That doesn't mean human beings are dualist by default. After all, all sorts of cultural concepts are ingrained in children by age, such as gender roles or moral concepts.
You're likely interpreting this as "evidence for inherent dualism" because you grew up with, or were extensively exposed to, dualist societies. A child raised in a monist society, which marks no ontological distinction between physical and spiritual, would likely give the same answers. They, and the researchers, would just interpret the results via that monist mindset.
E.g. monist societies with ancestor worship fully understand that there's a difference between the dead and the living,
and believe the deceased are taking an active role in the world of the living. They'd have no problems understanding what the kids are describing, and putting it into monist terms.
The upshot of all of that is that no matter how common and natural the notion of non-conscious 'material' stuff seems, it's not necessarily based on any sound empirical or logical grounds....
It's not based on
scientific research, but empiricism -- as in, knowledge gained via experience, rather than reasoning -- is much broader than science. Again, lots of people would claim that they directly witnessed what we'd call supernatural events, and thus claim they were using empirical methods to establish things that we reject today (e.g. humorism, confirmation of miracles etc).
Who said? As I noted to Watsup earlier, the reasoning "If brain then consciousness... no brain, therefore no consciousness" is wildly and obviously fallacious, known as denying the antecedant.
No, it's just an assumption that if you have a mind, then it has some sort of substrate.
If you're going to execute computer code, you need a computer. It isn't going to run on thin air. Right...?
Or: If you believe we are all part of Brahma's dream, then "Brahma" still has to be a thing, right...?
Your assertion would imply that mental stuff could never even in theory be present in artificial or extra-terrestrial intelligences...
I said nothing of the sort. I'm just saying that if you have mental activity, it has to have some kind of substrate. I see no reason why that substrate can't be silicon or some other physical substance.
which would make the
hard problem of consciousness that much harder!
Claiming that "minds need substrates" has no effect on that issue.