(This question is splited from another question as suggested by moderators)
Ever since reading this NewScientist issue on how even if for some beliefs that despite being based on falsehoods, can have actual impacts to the world via cultural influences, I started to wonder about the nature of belief, and by extension, unreal entities or concepts that have real impacts.
For example let's take the belief
Santa Claus is real
Next, while the jury on whether we have freewill is still out, a belief in freewill can reduce ethnical prejudice compared to a denial of it.. Therefore, regardless on whether freewill is real hence the belief "freewill is real" is true, there are real, measurable impacts no matter you deny or accept said belief.
- The above also suggests false beliefs or even more generally unreal entities can have real impacts, at least indirectly
What is a possible metaphysical explanation on why beliefs seemed to only ever act indirectly on other entities, that is, only via emergent or collective phenomenon like social phenomenon, why is it unable to act directly (such as physically, or via changing the perspective of an entity) except for the personal/subjective level?
Are false beliefs physical, given how they exert their casual power (at least) indirectly via social influences, or just abstract objects (they have the truth value of being false for almost all worldviews or does not corresponds to what is observed in an objective reality) which we can refer to but does not have any casual powers by itself?
NB: A psychological explanation can only explain why a belief can act indirectly and brought out the effects via the collective action of a community, but it said nothing about the (non)existence of beliefs that act directly and beyond the subjective level. This is why I suspect answering this later half of this question requires looking at belief as a metaphysical object with all its intrinsic properties being analysed, in particular whether it is abstract or physical as we could have said that the believer to be the one responsible for the causal power, and not the belief itself if belief is abstract.