It starts with the opposable thumb. This genetic quirk allowed some species to manipulate objects with greater precision. But it also required (or probably drove) an increase in neurological complexity which, inter alia, allowed for the development of imagination - the capacity to visualise things which did not exist. On the one hand, this allowed our ancestors to combine various items they found into more complex and useful forms. On the other, it allowed them to people the world with spirits. In between, it allowed them to manipulate other objects to make them more pleasant to look at or touch and to construct narratives.

Toolmaking, religion and aesthetics, all down to the thumb.

Just a theory, of course!