[Houshalter]

For tens of thousands of years we lived as tribes of hunter and gatherers. We are biologically programmed to form groups and hate other groups that are perceived as an enemy to our group. Evolutionary psychology is complicated and speculative, but it's quite clear we have evolved an ability to form strong feelings of hate towards other groups.

I like this quote from HPMOR:

>Because the way people are built,... the way people are built to feel inside -...is that they hurt when they see their friends hurting. Someone inside their circle of concern, a member of their own tribe. That feeling has an off-switch, an off-switch labeled 'enemy' or 'foreigner' or sometimes just 'stranger'. That's how people are, if they don't learn otherwise...

>You grew up in a post-World-War-Two society where 'I vas only followink orders' is something everyone knows the bad guys said. In the fifteenth century they would've called it honourable fealty... Do you think you're, you're just genetically better than everyone who lived back then? Like if you'd been transported back to fifteenth-century London as a baby, you'd realize all on your own that burning cats was wrong, witch-burning was wrong, slavery was wrong, that every sentient being ought to be in your circle of concern?