How can it teach us anything about human psychology if it never actually happened?
> It is not defamation to infer that a primitive group of people is, well, primitive.
Primitive doesn't mean stupid. In "Guns, Germs, and Steel", Jared Diamond said that nearly all the tribal peoples he met when doing fieldwork were seemed to be, on average, more intelligent, engaged, curious, and knowledgable than the average Westerner. (In his follow-up book, "The World Until Yesterday", he attempts to capture some potential wisdom that tribal peoples have that he thinks modern society may have lost.)
It's this confusion between "primitive" and "stupid" that is exactly the harm that he cargo cult story creates and perpetuates.