We don't know how doubt emerges from biochemical processes in the brain. We also don't know about the emergence of thought, qualia, and intentionality. — MoK
Maybe because of our approach.
All of these items you listed are mechanisms in an autonomously moving deterministic process which is transmitted by socialization generationally.
As you suggest, at the level of reality whatever the heck doubt is, is not what we're assessing here. A prehistoric human, like other animals lacked this 'artificial' autonomous process. When it faced a divergence in a path, it either used its senses and responded in accordance with its conditioning to follow the 'right' path, or it just moved forward indifferently. It did not have the pronoun to attach either congratulations for a right choice nor doubt with respect thereto.
We are assessing a thing we have over eons constructed and reconstructed, and transmitted from generation to generation, such that whatever real doubt is, has been displaced by it. The 'doubt' we are assessing is not that biochemistry, but the deterministic movement of images constructed and projected into this world of moving images--not world of natural conditioning where the chemistry is at play. And I realize they function together on a feedback loop, but we're really talking about the surface, the world of images, where d-o-u-b-t abides, with all of its triggering powers. I'm confident we're not going to find
d-o-u-b-t in any chemicals.
I'm saying (oversimplified for space and time) those images move deterministically. For humans born into history, confronted by a divergence in a path, if one path appears rugged and dangerous, the other smooth, and these are the only factors, reason, moving images of a specific variety, autonomously gets to work, and the easy path is selected. If a given person happens to defy reason, they did not. Their 'reason,' just as autonomously applied as conventional reason, the rugged so-called choice was triggered by moving images of xyz autonomously moving them to take the rugged path. Finally if one cannot choose, and 'reads' into experience, moving images called doubt, that too, is pushed upon the body at that moment, e.g., a balance of xyz's or conflicting structures, just as autonomously playing on the next step/no step as reason or defiance did.
In none of those cases is an agent 'choosing.' Its just stimulus and conditioned response. But built into the deterministic movements, is, because of the attachment of the image(s) to the pronoun, the Subject, giving the illusion of an agent/choice in what's really a deterministic process. So that in neither prehistory nor history is it valid for an animal to congratulate themselves for a choice or to curse bad choices or indecisions. It is all stimulus and (conditioned) response. It's just for human animals there is an illusion of a chooser and choice.