[musicale]

Hate is as natural as love for humans (perhaps more so) and is adaptive. Consider:

1. In-group bias, which shows up in babies

2. Pecking orders/social status hierarchies, which arise pretty much everywhere from birds to humans; they create a somewhat stable social structure but encourage animosity between those who peck and those who are pecked

3. Communities defining themselves by excluding others (see 1)

4. Scarce resources leading to fights for survival; people who threaten your very survival are easier to hate

5. It's hard to fight people you empathize with, so demonizing/dehumanizing them is necessary if you want to win/survive