In game theory, cooperation is a dominant strategy and evolves consistently. Slave owners and other injustice committing humans often invoke "human nature" out of trying to cope with their knowledge that it is wrong but whatever trauma or other thing makes them do it anyway, to absolve themselves of agency.
reply(To be clear, not targeting you personally here, but targeting the rhetoric and fallacy)
Cooperation is an unstable strategy. If everyone else is cooperating and not punishing defectors much, defecting is vastly better for you.
replyIf everyone else is defecting and you can cooperate with a few people, that's slightly better for you. Hence we have high-trust and low-trust societies, gatekeeping, etc.