Tribalism: The Feature That Became a Bug

For most of human evolutionary history, belonging to a group was not optional. It was survival. Being cast out of the tribe meant facing predators, starvation, and the elements alone. The human brain developed deep, powerful machinery for tracking group membership, maintaining loyalty, and treating outsiders with suspicion.

That machinery is still running, in brains that now inhabit a world of seven billion people, the internet, and political systems no ancestral tribe ever had to navigate.

The minimal group paradigm, developed by Henri Tajfel in the 1970s, showed just how thin a thread is needed to activate tribal psychology. Tajfel assigned participants to groups based on essentially random criteria — which of two painters they preferred, or even just the flip of a coin. Despite having no history, no shared interests, and no meaningful connection, participants immediately began favouring their ingroup and discriminating against the outgroup in how they allocated resources.

You do not need religion, race, nationality, or ideology to trigger us-versus-them thinking. You need almost nothing. Once a group identity is established, the brain goes to work justifying preferential treatment for the ingroup and suspicion of the outgroup. Logic and fairness become tools used selectively in service of group interest.

In modern societies, tribal instincts attach to political parties, sports teams, online communities, professions, and ideological movements. The content of the group belief matters less than the group membership itself. People will shift their stated opinions on policy issues depending on which party they are told supports them. They are not reasoning about policy — they are signalling loyalty.

Social media has weaponized this. Platforms optimized for engagement discovered that outrage, threat, and ingroup-versus-outgroup content generates more engagement than nuanced, complex thinking. Tribalism is profitable. So the feed serves you more of whatever inflames your group identity, and the opposing group becomes increasingly monstrous in your perception.

The antidote is not to abolish group identity — that is not possible and arguably not desirable. It is to deliberately cultivate overlapping identities, personal relationships that cross group lines, and epistemic practices that force engagement with evidence over loyalty. These are cognitively expensive habits. They go against the grain. They are also the only way to think clearly in a world that profits from your tribe.