It seems like this notion of "tribe" is a vague concept that you can redefine at will to support your argument or reject counterexamples that don't fit your narrative.
-k
We are instinctively tribal. Jonathan Haidt talks a lot about that, and numerous studies have shown we prefer to be around, to live around, those who are 'like us'. The more like us they are the more kinship we feel towards them. And the reverse is also true. Why do we give a million dollars to the families of some hockey players whose bus hit a truck out west but completely ignore the families of 22 people who died in a bus crash in Uganda the other day, or the 27 people who died in a bus crash in India last month. I bet none of you have even heard about them. We see the ones in Humboldt as being 'like us' and see ourselves in them and that gives us more empathy.