The Early Christian Strategy: SOLVED

the hidden power of turning the other cheek

In a recent post, Scott Alexander asks: “How could it be that early Christian’s flourished when they only play COOPERATE, isn’t TIT-FOR-TAT more optimal?” I think I have a good answer to this. And like the Bible, it comes in two parts:

(I recommend you read Scott’s article first if you haven’t already, otherwise some of this one might not make sense.)

1. Game Theory

COOPERATE crashes in a world of DEFECT. But in a TIT-FOR-TAT environment it can survive. TIT-FOR-TAT won’t defect spontaneously.¹² You can just continually cooperate with him, and the fact that you are running different algorithms under the hood doesn’t matter. DEFECT could come in and beat COOPERATE to a pulp, but in the historical case of Ancient Rome he wouldn’t be entering into a tournament of COOPERATE. Most Romans are still TIT-FOR-TAT and would retaliate hard against DEFECT

But what if you become a little smarter and defect only against Christians. Call this EXPLOIT. This might work in a lab session where you have large number of rounds to figure out what your opponent’s strategy is, but in real life, people will just stop interacting with you if you take advantage of them a few times. So the only way to EXPLOIT is to observe how Christian’s interact with others and to deduce that they play COOPERATE.

Now you have introduced another element to the game: Third party observation. But that very mechanism could be the downfall of EXPLOIT. Whenever EXPLOIT plays defect against COOPERATE, TIT-FOR-TAT is there to observe. Going forward, he will categorize EXPLOIT as a dishonest player, and initiate defection the next time they interact. EXPLOIT will argue that TIT-FOR-TAT hs nothing to worry about, he only targets COOPERATE. But a prudent TIT-FOR-TAT player won’t believe him, because he could very well be a DEFECT player trying to trick you³. EXPLOIT players could try to become common enough to overcome that presumption, but to that they need to reach a critical mass while they are pushing against the Nash equilibrium (hard!). The Amish practice non-resistance (COOPERATE) today, but when you see someone stealing horse buggies in Lancaster County, you (a TIT-FOR-TAT player) don’t think to yourself “Must be one of those EXPLOITers, nothing to see here”.

Critically, this entire strategy only works for COOPERATE when they are a minority. If they become the overwhelming majority there are not enough TIT-FOR-TAT players to do the enforcement on their behalf. This is probably a major reason that Christians at least partially abandoned COOPERATE when they went mainstream. it was later revived by Anabaptist (such as the aforementioned Amish) and other Christian sects such as Seventh Day Adventists, but they too were only minorities wherever they lived.

It also likely wouldn’t work in honor cultures. There each man is expected to enforce his own rights. Honor cultures are perfectly happy to let EXPLOIT get away with it. But the Romans (particular Roman Urbans) where settled people, that had much less honor culture than the Greeks used to have around when the Iliad and Odyssey where composed.

So we see how the cost of playing COOPERATE could be reduced, but what is there to gain from adopting this strategy? If you have a perfect spherical Christian in a vacuum, it does not matter much. But in real life people make mistakes. People have disagreements about who is right in disagreement. People accidentally hurt each other. All kinds of things happen. TIT-FOR-TAT gets caught in a defect loop whenever this happens. TIT-FOR-TAT-WITH-FORGIVENESS does better by escaping the loop after a bit, but COOPERATE escapes immediately. COOPERATE will also develop a reputation as a honest dealer. Which makes people more likely to work with him and to give him the benefit of the doubt whenever disagreements arise. Quaker Oats weren’t actually founded by members of the Society of Friends, but by a German and a Canadian looking to use the good reputation of Quakers to their advantage.

2. CREDs

The science of religion has done research on what makes people religious. What they found is that "Credibility enhancing displays" (CREDs for short) are the most likely predictor. If your father is a Mormon and tells you he spend a year learning Spanish and converting people in Guatemala, you're likely to take him serious when he tells you it is important to be Mormon. This is an evolutionary adaptive attitude to have in a Secret To Our Success sort of way. Suppose someone tells you (not) to do something in a costly because of reasons which you cannot independently verify. You should be more trusting of them if they themselves are willing (not) to do that thing, or similarly costly things for the same reasons.

In this account, consistent cooperation in the face of defection is extremely high in CREDs. The CRED epitome is martyrdom. The martyr pays the ultimate price, for no visible benefit, and the Romans publicly displayed that sacrifice to all that wish to see it. It is no wonder that Christians really centered the martyrdom of the saints and Jesus himself in their religion. They still do (at least the Apostolic denominations). But those stories would feel a lot more visceral to ancient Christians that have the Roman authorities breathing down their necks and to who knew the martyrs personally. This may explain the difference in fanaticism between modern and ancient Christians. And while the Romans had bouts of prosecution, they had more of a dont-ask-dont-tell policy most of the time. That combination created enough martyrs to completely CREDload Christianity, while giving it the opportunity to recover.

Conclusion

These two reasons taken together tell a convincing story of how Christianity prevailed, even though it adopted a strategy that seems sub-optimal at first. Even as Christians turned the other cheek, their neighbors may not. And those neighbors may suffice to create herd immunity against defectors for the society as a whole. In the mean time Christians could harness their positive reputation to function into more positive sum deals. The only defection they really faced is persecution and bullying, but those helped strengthen their faith. Outsiders may even convert in awe of their bravery.

1. Yes, the Pegan Romans did persecute Christians, but only in retaliation for the latter’s refusal to participate in rituals that the Pegans believed to be neccecery to maintain the Empire (“These damn Christians refuse to celebrate Saturnalia, do they want to bring plague upon us?”). From the perspective of the Romans, they’re just tating the Christian’s tit.

2. In my post I will use “COOPERATE”/”DEFECT” to mean the general strategy of always cooperating/defecting. And I will use “cooperate”/”defect” to mean the individual move.

3. Also, the sort of character that would exploit people is probably more likely to screw you over in all sorts of other ways.