Purity Spirals

Take a group organized around a good cause. Nobody in it is cynical. Everybody is sincere.

Now add one ordinary feature. Inside the group, status comes from visible commitment to the cause.

That is enough. Nothing else is required.

How It Runs

Five steps, and they repeat.

Commitment becomes the currency. Standing inside the group is earned by demonstrating more dedication than the average member.

There is no ceiling. Nobody can be too committed to a good cause. So the standard is free to move in one direction only, and it does.

The safe position is slightly ahead of the line. If you are behind it you are suspect. If you are level with it you are unremarkable. So the sensible thing, for each individual person, is to be a little stricter than the current standard. Which moves the standard, which means everybody has to move again.

Accusation is cheap and defense is expensive. Accusing somebody of insufficient commitment costs you nothing and demonstrates your own. Defending them transfers the suspicion to you. So accusations are made freely and almost nobody defends anyone, which everyone correctly reads as consensus.

The moderates go first. The people most uncomfortable with the escalation are the first to leave or fall silent. Their departure lowers the average and raises the standard, which makes the next group of people uncomfortable. The group gets more extreme without any individual member changing their mind.

Lesson 3.4 gave you the sentence for this. Situations shift the distribution, not the individual. Replace every person in a group running this pattern and the pattern continues, because it was never in the people.

The Reliable Symptoms

Groups in a spiral start spending most of their energy on their own members rather than on their opponents.

The purges become retroactive. Positions that were mainstream in the group three years ago are now evidence against you, and having held them then counts even though everybody did.

Expulsions concentrate on the people closest to the group's aims rather than the furthest. An opponent is not a threat to your standing. A near ally who defines the cause slightly differently is a direct competitor for what counts as real commitment, and gets treated far worse than any outsider.

And the language shifts from what the group is for to who is not really part of it.

It Is Not A Political Thing

This has to be said plainly, because most people have only seen it in the direction they already dislike.

The French Revolution produced the clearest case anyone has. The revolutionaries executed the moderates, then the faction to their left, then the faction that had executed that faction, and finally the man who had presided over the whole sequence. Each round was carried out by people who believed the last round had not gone far enough.

Mid twentieth century separatist religious movements developed a doctrine of second degree separation, which required breaking fellowship not only with the impure but with anyone who had failed to break fellowship with the impure. That produced congregations that split, split again, and ended as a handful of people certain that everyone else had compromised.

Small revolutionary parties in the 1970s spent most of their existence in factional expulsions and produced almost nothing else.

And it happens where there is no politics at all. Hobby communities, fan communities, diet and wellness groups, and craft forums generate the identical dynamic over questions of authenticity that no outsider could even follow. That is the best evidence that this is structural. A group of people arguing about the correct way to knit can run the same machine as a revolutionary tribunal, because the machine does not care what the cause is.

When It Is Not A Spiral

Groups do need boundaries. Some people genuinely should be removed from some groups, and calling every expulsion a purity spiral is a way of protecting people who should not be protected.

So here is what tells them apart. Is the standard moving, or is it fixed and being applied? Is it being applied backward to conduct that was acceptable when it happened? Is the accused person's defense being treated as further evidence against them? And is the group now spending more of its effort on its own members than on the thing it exists to change?

A group with real boundaries can tell you what they are in advance. A group in a spiral cannot, because the boundary is wherever the front edge happens to be this month.