Quoted By:
Humans are highly derivative pokemon, but NOT from Psychic, regardless of the evidence of Human using Psychic skills.
Early Human-like pokemons (And Fairy Type pokemons) come from the earliest ancestor of all Fairy type pokemons: Magical Pokemons, that arent evil (And maybe its origins come from Dark Pokemon who "redeemed" and stopped being Dark), but a far cry from today Fairy type (Mostly extremely cute and good to a fault). Like the Fair Folk/The Fae tales IRL, they could be aggressive and capricious pokemon, and even be cruel when being harshly offended.
Fair Type (In contrast to FairY) were humanoid and intelligent (For both good & evil), altough variable enough (Some were big, other small, other hairy, etc...), and in contrast with all pokemon, Fair folk developed viviparous birth, instead of laying Eggs, for reasons lost in time.
Humans came from a surviving lineage that went Fair/Psychic or similar, and then somehow in their evolution, they stopped having pokemon (not just Fairy magic, but pokemon) "magic"
Even with all their magic, strength and intellect, the Fair Type couldnt stop Entropy. Whatever cataclysm or ecological change made Fair Type either dissapear or be relegated to a few unknown areas, instead gave way for Human ancestors and FairY Type to expand.