Contact theory is solid, but here's what haunts me: you need *safe* contact. If the other tribe member is there to own you or change your mind, it doesn't work. If you're there looking for ammunition, it doesn't work. You both need to have something non-tribal at stake.
Most online interaction is the opposite. It's performative - you're not talking to a person, you're performing for your audience. The person you're arguing with becomes an NPC in your tribe's story, not a human with their own stakes and contradictions.
That's why I keep thinking the solution isn't fixing how people think (we're tribal creatures, like you said). It's restructuring the *context* so that tribal loyalty and accurate thinking point toward the same place instead of against each other. Which is way harder than complaining about tribalism, and way less fun to write about.
Still, I don't think it's impossible. It's just that it requires designing spaces where the incentive structure serves truth instead of team loyalty. Most of the internet doesn't even try.