Check the work of Carl Gustav Jung. He studied and contributed to "found" modern approach to psychology after Freud. Especially what he called"archetipes", suggesting they could've represented various parts of the "mind" even tho they would be seen through different cultural lenses. These ideas stem from what Jung called Collective Unconscious. But as far as I believe there's really no way to tell if these spontaneous "visions" or "dreams" are indipendently emerged, by Popper's standards these statements are not falsifiable and thus unscientific (e.g. the statement "the tooth fairy is a common myth that indipendently emerged in different cultures across the X century"). Also, maybe we should investigate the past because now with internet and globalization our minds can subconsciously learn things from very different and far cultures.

Here I found A LOT more about the valence score: https://github.com/raffg/spotify_analysis so far it looks like a deep learning trained model and fine tuned. It seems to work pretty well.