The ‘Big Mistake’ and ‘Grand Deception’ Hypotheses: Alternatives to CMLS?



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If CMLS (cultural multilevel selection) doesn’t help to explain human social evolution, how did human ultrasociality (ability to cooperate in huge groups of unrelated individuals) evolve? Steven Pinker falls back on the ‘usual suspects,’ kin selection and reciprocal altruism: “The huge literature on the evolution of cooperation in humans has done quite well by applying the two gene-level explanations for altruism from evolutionary biology, nepotism and reciprocity, each with a few twists entailed by the complexity of human cognition. … A vast amount of human altruism can be explained in this way.”

The problem with these two theories is that they cannot explain the evolution of human ultrasociality. Even in bands of hunter-gatherers the majority (three-quarters, according to recent estimates; Hill et al. 2011) are unrelated to ‘ego,’ and of course the average relatedness among huge societies of hundreds of millions of individuals is indistinguishable from zero. As to reciprocity, models show that it can work in small groups of few individuals, but it breaks down completely once the group  size exceeds ten. This was clear to such eighteenth century thinkers as David Hume:

Two neighbors agree to drain a meadow, which they possess in common; because ’tis easy for them to know each other’s mind; and each must perceive, that the immediate consequence of his failing in his part is abandoning of the whole project. But ’tis very difficult and indeed impossible, that a thousand persons shou’d agree in any such action; it being difficult for them to concert so complicated a design, and still more difficult for them to execute; while each seeks a pretext to free himself of the trouble and expense, and wou’d lay the whole burden on others.

Although Pinker does not explicitly acknowledge this point, he seems aware that straightforward “nepotism and reciprocity” cannot explain extensive cooperation in groups of millions of people. Here’s where he brings in “cognitive twists.” The basic idea is that human propensities for cooperation with kin and in reciprocal settings are manipulated by other humans.

This is a version of the ‘big mistake’ hypothesis (as Boyd and Richerson have characterized this current in the Evolutionary Psychology theorizing), according to which people are somehow ‘fooled’ to cooperate with millions of other members of their society because they mistakenly consider them as relatives.

The version advocated by Pinker can be called the ‘Great Deception’ hypothesis. He uses this to explain away suicide terrorism. But what about volunteering for military service in times of war? Pinker writes, “Even in historical instances in which men enthusiastically volunteered for military service (as they did in World War I), they were usually victims of positive illusions which led them to expect a quick victory and a low risk of dying in combat.” But that does not describe the actual historical cases, e.g., volunteering by the British men during WWI. The British continued to volunteer long after it became abundantly clear that there will be no quick victory and that the war was a slaughterhouse. The British authorities did not need to implement the draft until 1916 (for a more nuanced discussion of this case, see my War and Peace and War).

Furthermore, a big part of Pinker’s argument is that it is “other humans” (presumably, political elites) who fool common people to fight and die to advance their nefarious ends. But there are many counterexamples. To give just one, the ruling elites of the Roman Republic (the senatorial class) bore their fair share (and perhaps even more) of the burden of Rome’s continuous warfare. The senatorial class fought and died on the front lines during the battles of the Second Punic War. Proportionately, the Senate lost more members than common citizens in such defeats as Lake Trasimene and Cannae. So who was fooling Roman patricians to sacrifice their lives for the sake of Patria?

There are many other examples in cultural evolution in which political elites (that is, the segment of the society that concentrates power in their hands) end up sacrificing their fitness. In a recent paper, Joe Henrich and coauthors analyze the spread of monogamy using the framework of cultural group selection. Without such a perspective it is very difficult to understand why would male elites agree to limit themselves to a single wife. Since the number of offspring left by a human male is determined primarily by the number of wives he has, one would expect that polygamy would greatly benefit wealthy and powerful males. Yet monogamy spread, and Henrich et al. make a credible case that it did so by the process of cultural group selection.

In the final analysis, research programs (sensu Lakatos) are judged by how productive they were. The CMLS framework has motivated a vibrant program of model development and empirical tests. The ‘Big Mistake’ and ‘Great Deception’ hypotheses of the Evolutionary Psychology have failed to lead to similar developments. It is not even clear to me how we could test Great Deception explanations empirically (can it be falsified?). In contrast, the young discipline of CMLS has already shown that it can generate testable (and empirically tested) predictions. In the end, I will not be surprised if the CMLS theory ends up completely transforming our understanding of human history.

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Tim Tyler

Most reciprocity involves groups of two individuals. However with enough pairs of individuals large scale cooperation can easily be produced. The idea that reciprocity doesn’t apply to large groups is just muddling together two conceptions of group size (one being the parties to particular cooperative acts, the other being the size of the population they are part of).

I’ve been over this exact same point before on this very site. See comments 5 and 6 on “Cooperation in Humans: Is It Really ‘Strong Reciprocity’?” for a more detailed critique.


Remember that group selection depends on relatedness too, just like kin selection.
Relatedness being “indistinguishable from zero” rules out both group selection and
kin selection hypotheses.

Of course, in practice, large groups usually share memes, so members of the armed forces are cultural kin – and it is only DNA-relatedness which is low. Soldiers are dressed to resemble each other, using fictive kinship (actually cultural kinship) and feel as though they are “brothers in arms”. The patriotism memes that manipulate the soldiers are the close kin of the patriotism memes in the school teachers, drill sergants and politicians that use propaganda to indoctrinate the kids into fighting for their country. The memes in the soldiers die, but their fertile immediate kin live on – in the form of copies in other bodies.


To ask “who was fooling Roman patricians” may be the wrong question. Most patriotism memes are engineered by those in positions of power to manipulate others into acting on their behalf. However, once released into the population these memes take on a life of their own – since they are designed to use “viral” mechanisms to reach as many people as possible. Religions and chain letters work in a similar manner. There’s *usually* some humans benefitting at the start of the chain – but that may be long ago, and the memetic engineers might die before their memes do.


To quote from my response to the “monogamy” paper: “A simple explanation for monogamy is democracy. Polygamy is deleterious for 90% of males and probably most females too. The few males it benefits may be powerful, but they are simply out-flanked by the rest of society. This explanation is simple, obvious – and it doesn’t invoke group selection.”


‘Big mistake’ and ‘great deception’ look like bad terminology to me. The basic idea here is “manipulation” – by either people or cultural elements. IMO, scientists should be using that word.

Peter Turchin


1. A whole bunch of pairs of reciprocators doesn’t make a cooperative society. How would you get people volunteering for war on the basis of binary pairs of rational agents? You can’t. Even a coordination problem is difficult once you go well beyond pairwise interactions, as the quote from Hume illustrates.

2. You have a quirky definition of relatedness, which has nothing to do with biological relatedness (the usual meaning of the term). But it looks like we are talking about the same thing, you just use terminology that I don’t like.

3. The problems with the theory that memes manipulate humans are manifold. But the main one is that it’s not falsifiable. As I argued in this and other posts, CMLS leads to a fruitful research program. How does the ‘manipulation hypothesis’ lead to novel predictions that could be tested with data?

4. Well, but explaining democracy is as problematic as explaining monogamy. Why should power elites give up their power? And most historical societies to which monogamy spread were far from democratic.

5. Perhaps ‘manipulation’ is a better name. But whatever you call it, it doesn’t yield testable hypotheses. It’s all post-hoc explanation. If a hypothesis explains everything, it explains nothing.


My claim was that “pairwise” reciprocity works just fine in large groups – not that it explained military volunteering.

Deceptions are, by their nature, not easy to detect. However, people can detect them. We have whole organisations devoted to detecting deceptions. We know that much military propaganda consists of lies. We can interview the mothers of military volunteers – to see if they are party to the deception. Frankly, there’s not much in the whole of the social sciences that is untestable. Hypotheses can be *vague*, but if you pin an idea down, you can usually test it.

One related effect is in the 2012 “Education and Military Rivalry” paper. This illustrates how states facing war use indoctrination in primary schools to make soldiers for them.

Coalitions of numerous weak individuals overpowering strong individuals is a basic phenmomenon. It is also common in other primate groups, and it has precious little to do with group selection.

Good evidence for group selection normally needs to involve traits that are deleterious within groups, but help groups to compete against other groups. Monogamy looks as though it scores poorly here – since disadvantage within groups has not been demonstrated. Rather, it looks as though monogamy is advantageous within groups – on average. This makes it poor quality evidence in favour of group selection.

IMO, best not to say that culture is not “biological”. Rocks are not biological. Culture is 100% biological.

Artem Kaznatcheev

Do you have a reference or link to Henrich et al.? Or even better, a short summary of the mechanism?

Peter Turchin

Here are the key refs:

[3] Scheidel, W. 2009. A peculiar institution? Greco-Roman monogamy in global context. History of the Family 14:280-291.

[4] Henrich, J., R. Boyd, and P. J. Richerson. 2012. The puzzle of monogamous marriage. Phil. Trans. R. Soc. B 367:657-669.

I will probably do a post on this issue soon.

charles brough

It surprises me that the academic world won’t deal with the role of us having ideological systems in common, the role it plays in uniting its members and thus expanding the small, hunting-gathering sized groups that millions of years of evolution shaped us to life in. We do not defy our brain-stem repitoire of social instincts. They provided all of our motive and our primate communicative system of gestures, facial expression, and sensititivty to the will of the group (or herd action or swarming in other animal groups). We redirect them successfully to the larger group by in common sharing the same belief system.To list the social instincts is easy from studying the available wealth of primate behavioral studies—especially of the chimp.

Ancient Sapien’s hunting/gathering groups functioned successfully, but when we developed speech, we could evolve ideological systems that enabled us to think in common and in much larger troops, even later on in villages, towns, cities and finally kingdoms and nations.

The explanation has nothing to do with kinship! Even “altruism” is a phoney explanation. Part of our small-group nature is for the members to seek status and for the alphas to protect the group, control the male juveniles and keep order.

Tim Tyler

Re: “It surprises me that the academic world won’t deal with the role of us having ideological systems in common, the role it plays in uniting its members”

There are some treatments of that topic out there. Some are even within academia. E.g. search for “cultural kinship” and “kith selection”.

Re: “The explanation has nothing to do with kinship!”

Well, you should consider the possibility that your perspective is guiding you away from the material you are looking for. Shared ideologies may have little to do with blood relatives – but it has a *lot* to do with memetic relatedness. Memes have kin too!

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