Human cooperation, I’ve argued before, is remarkable and unlikely. Even more remarkable is that it ever got beyond the tribal scale of a couple dozen to a couple hundred people, given that the institutions necessary to sustain cooperation at that scale are very different from those necessary to sustain anonymous and large-scale cooperation.
Many of those institutions for small-scale cooperation strike us today as distasteful. Gossip, for example, according to Bowles and Gintis, is essential for making information public within the tribe. Nobody gossips, you have no way of knowing who’s trustworthy and who’s not, and the tribe falls apart.
Our own perspective on gossip in the modern era probably comes closer to these strictures:
This contrast raises several questions: First, how does modern civilization get along without integrative institutions like gossip? Second, and more difficult, when you get rid of small-scale integrative institutions, how do you make sure you jump to large-scale cooperation, rather than just losing cooperation entirely?
Unlikely as it was, Christianity seems to have accomplished just this. The deliberate suppression of the mechanisms that keep small scale groups together resulted – somehow – not in the extinction of its own institutions, but in a transition to more anonymous and large-scale cooperation.
Tribal institutions for ensuring cooperation all have certain qualities. First of all, they have to be relatively low cost and informal. If it’s too costly to ferret out non-cooperators and punish defectors, nobody will do it. Second, they have to be inherently pleasurable. Paul and James wouldn’t have had to dwell so long on gossip if people didn’t enjoy doing it! In general, there’s evidence that people do indeed find punishment inherently pleasurable, and that doing so is necessary to sustain cooperation at any scale. These qualities ensure that anyone can take action against a non-cooperator, so that cooperation within the group is sustained by the widest possible net of social pressure. If Joe isn’t pulling his weight, he feels the pressure from everyone to get his act together.
More importantly, the norm of “an eye for an eye” – or “tit for tat” – is absolutely crucial for keeping a group together. If you cheat me, I’m willing to forgive you, but only after punishing you to make it clear that doing it again won’t pay.
Christianity, of course, boldly rejected this strategy. Jesus says in Matthew 5:39 “But I say to you, do not resist an evil person; but whoever slaps you on your right cheek, turn the other to him also.” Cooperate with non-cooperators! Don’t punish defectors! How could cooperation possibly be sustained with a norm like that?
Well, it turns out Christianity does have a method of dealing with non-cooperators after all:
If your brother sins, go and show him his fault in private; if he listens to you, you have won your brother. But if he does not listen to you, take one or two more with you, so that by the mouth of two or three witnesses every fact may be confirmed. If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector.Matthew 18:15-17
Compare this strategy to something like gossip or “an eye for an eye”. Confronting a defector is extremely psychologically costly compared to gossiping. And if that doesn’t work, the next remedies are even more costly! Everyone is pretty much effective at gossip and shunning. Not everyone is articulate enough to manage a confrontation like this well enough. Not everyone is patient enough to keep cooperating while the situation escalates through the formal channels of the church leadership. Only a few people in any group are going to be able to effectively manage the process in Matthew 18. So they specialize into a permanent formal governance body that takes over when things escalate. This is very different from the mostly ad hoc mediation that occurs in intra-tribal conflict.
What this means is that Christendom accustomed its lay members to 1) unconditional cooperation, and 2) faith in a small minority of administrators who specialize in dealing with defectors. In other words, Christianity acclimated its adherents to life under a state rather than life in a tribe. It’s probably no coincidence that the development of regular cooperation under strong but non-despotic states developed in Europe, and to this day exists for the most part only in those parts of the world with Christian and European heritage.
Indeed, as others have noted, the Catholic church, quite apart from any theological basis, deliberately extirpated even more tribal-style integrative institutions and centralized their enforcement to itself. Cousin marriage was important in most of the world – and still is in much of the non-Western world – as a way of cementing intra-family ties. The Catholic church banned it and elevated the nuclear family as the familial ideal. Elite families maintained their status by passing privileges and offices to their children, so the Catholic church mandated priestly celibacy. There should be no large and persistent clans competing with the formal Church hierarchy for administrative control.
Though maintaining cooperation with a formal administration rather than diffuse enforcement entails much higher fixed costs in terms of the institutional apparatus necessary to make it work, the gains in terms of the marginal costs of enforcement were evidently large enough to make a dramatic explosion in the scale of cooperation possible.
Finally, I should note that the important innovation in Christianity was not whether defectors get punished, but who punishes them. Defectors very much were punished during Christendom’s heyday. If the administration itself should eventually qualm to punish defectors, then in the long run cooperation can’t be sustained on any scale.