Note that Ataöv suggests that differences don’t cause conflicts; conflicts create differences. Members of a group seize on differences in order to affirm their own identity. A feedback loop ensues: differences are invented or enlarged, which stimulates further animosity, which magnifies differences, and so on.
There is evidence that political radicalism correlates with high anxiety, which seems to push people towards the security of a rigid political identity. Some folk just get very anxious if they don’t know where the boundary between their group ends and the other begins. They want to be able to say I’m with these guys. And that often means saying, I’m definitely not with those guys standing next to me.