It’s evolutionary to see danger in strangers because historically it was better to overestimate danger then underestimate it for your survival. You can only react once if someone hits you with a stone from their back. So people and groups overestimate danger that they will be hurt/diminished in some way and then attack when they see the slightest sign of a threat. It can be used to manipulate crowds, just say their children are in danger because of the out-group. Can really recommend the book on the exact mechanics of anger by the most influential psychologist of our times https://www.amazon.com/Prisoners-Hate-Cognitive-Hostility-Vi...
