The complexities of cultural evolution

cultural evolutionCultural evolution is a buzzword that gets thrown around a lot, even though, unfortunately, we still struggle to come up with a coherent — and testable — theory of how culture evolves. These days the word “evolution” is used in direct analogy with biological evolution, and particularly Darwinian processes, but it is far from clear if, and to what extent, cultural evolution is really analogous to its biological counterpart.

In a recent essay at The Philosophers’ Magazine Online I take on this topic by way of analyzing a carefully written paper by Alberto Acerbi and Alex Mesoudi, published in Biology and Philosophy, which attempts to clear the air from a lot of confusion in the field of Darwinian cultural evolution.

Acerbi and Mesoudi make clear what the problem is: “Cultural evolution studies are characterized by the notion that culture evolves according to broadly Darwinian principles. Yet how far the analogy between cultural and genetic evolution should be pushed is open to debate.” The bulk of their paper is an attempt to contribute to that debate by clearing up a lot of confusion that has arisen in the field when people talk about specific mechanisms of cultural evolution, and in particular the difference between cultural selection and cultural “attraction.”

Cultural selection is “a process of selection between different variants (e.g. beliefs, ideas or artefacts) or models (referring to people from whom one can copy).” The alternative is a situation in which “the permanence of some cultural traits occurs not due to high fidelity cultural transmission but instead due to the existence of stable ‘cultural attractors.’”

One of the issues I discuss in my commentary is that of what, exactly, counts as “Darwinian” evolution. “Darwinian” is a specific modifier of “evolution,” so we cannot simply equate Darwinism with evolution. Evolution, in the broadest sense possible, simply means change over time. As in the universe has changed since the Big Bang. But that is not a theory of mechanisms, it’s a neutral description. Life also evolved in that general sense of the term, but if that were all that Darwin said we wouldn’t have a science of evolutionary biology.

I summarize and discuss Richard Lewontin’s famous formal definition of Darwinism, and find that the concept has difficulties being applied to culture because we so far lack a crucial component of biological evolutionary theory: some sort of functional ecology of cultural traits, something that allows us to predict the “fitness” of a trait independently of the empirical observation of whether the trait does or does not thrive in a population. Without this independent assessment of fitness, evolutionary theory reduces to a tautology: it predicts that the fittest will be the one who survive, and defines the fittest as the one who have, in fact, survived.

Ultimately, it is still very much an open question whether we can develop a coherent Darwinian theory of cultural evolution, or whether it may be better to abandon the analogy with biological evolution and recognize that culture is a significantly different enough beast to deserve its own theory and explanatory framework. Of course, cultural evolution is still tied to biological evolution, for the simple reason that we are both cultural and biological creatures. But we may have a long way to go before untangling the two and arriving at a satisfactory explanation of how precisely they are related to each other.

P.S.: one of the authors of the article I commented on, Alberto Acerbi, did a nice and constructive commentary of my TPM essay, here.

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Categories: Philosophy of Science

110 replies

  1. Hi Socratic,

    And, given that memes were presented as a scientific idea (albeit “in utero,” perhaps), if the “science of mimetics” is ditched, what’s left?

    As I see it, the big difference is that DNA replication has a very low error rate (wiki says: “Together, these three discrimination steps enable replication fidelity of less than one mistake for every 10^9 nucleotides added”).

    I’d only be guessing at the error/mutation rate of “meme” replication, but that guess would start at about eight orders of magnitude higher. That means that the gene/meme analogy, while entirely valid, doesn’t get you very far at all.

    What I don’t agree with is the idea that something is “science” only if it is nice and easy, with a hi-fidelity replication making it amenable to fairly simple mathematical modelling. Of course those scenarios are where science makes progress most easily, just because they are easier. But attempting the hard stuff is still “science” even though it is harder!

    I also don’t think that Dawkins has “ditched” the idea of memes. Rather, he perhaps realises that the idea has rather limited utility (owing to reasons such as the ones I’ve just given). But then. other than a couple of footnotes where he has tried to push the idea, his claims for it always have been limited and tentative. It clearly is not an all-encompassing theory of human culture and was not claimed as such. It remains, though, an insightful idea that is useful when thinking about culture (and it is often the critics who over-interpret the idea).

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  2. @Coel

    > But attempting the hard stuff is still “science” even though it is harder!

    OK. But sometimes there isn’t much point in making the attempt, because the domain is just too messy. Like trying to make a science of the study of literature. It’s not really conceivable that we could develop objective measures of the things we deem important, such as insight or artistic merit. The things we can measure, e.g. the frequencies of certain words over time, are of relatively little importance in comparison.

    If you attempted to study literature in this way, you might be doing science, but I don’t think what you produced would be very worthwhile.

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  3. DM: The modern neo-Darwinian synthesis incorporates genes, which Darwin didn’t, remember, And memes were dreamed up as a direct analogy.

    So, no, we can only (if that) talk about “Darwinism” in cultural evolution if you mean only the Origin, and not the modern neo-Darwinian synthesis.

    I don’t see that as of real value, even if we can do that much. As noted in one of my first comments, that still leaves a mental/intellectual straitjacket of following a clearly inadequate analogy. It’s easier to start fresh.

    Coel: Error rate isn’t an issue, if there were memes, as long as the error rate were low enough to ensure transmission of a meme were any amount higher than background noise.

    While, per Massimo, who has discussed this error in some way in various works, defining science is not always easy, it generally includes things like hypotheses that are testable vs. a null hypothesis, falsifiablility, etc. Per DM, if you have something even “messier” than the social sciences as they now are, AND, which can’t meet those basic issues of “doing science,” then it’s not science.

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  4. Hello Mark Sloan,

    I’m sure that I’ve seen you around somewhat, but given this particular thread and a glance at your site, I’d very much like a discussion with you. Time has nearly expired here so I will try to engage you at your site, though if you like you can reach me by email: thephilosophereric@gmail.com.

    I’m very interested in receiving qualified assessments of my own model of the morality dynamic. I do agree with your position that morality evolved to promote cooperation strategies, though I also attempt to get even more fundamental by theorizing the specific mechanisms that we’ve been given to bring this about. I’ve come to see morality as a product of two separate varieties of sensation. One of them is “empathy,” or the conforming sensations which we experience when we perceive positive/negative sensations in others. Then the second concerns the sensations which we experience when we theorize what others are thinking (Theory of Mind). Thus even morality associated with the horrible female genital mutilation that you’ve mentioned, would not truly be a spandrel from this particular definition. Note that as a social expectation there should be great ToM pressure to have the procedure, and beyond other forms of punishment for disobedience. In the end I see morality as a tool that evolution developed to help the naturally capitalistic conscious entity, nevertheless develop cohesive societies.

    I should also mention that my thoughts on morality are just a small part of a much larger theory regarding our nature. I believe that our mental/behavioral sciences are still in need of founding theory from which to function, and therefore have been trying to shake others out of the standard notion that the academy is working reasonably well in this regard today. I do hope that you’re up for pondering some radical ideas!

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  5. Philip, on something like the culture of 7 billion humans, might not computer modeling hit Gödelian issues? Or any attempt to fully model human culture?

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  6. Hi Socratic,

    > DM: The modern neo-Darwinian synthesis incorporates genes, which Darwin didn’t, remember, And memes were dreamed up as a direct analogy.

    I have a different, perhaps controversial take on this. I do not see memes as directly analogous to genes specifically. Genes are replicators, organisms are replicators and memes are replicators. The key thing here is how replicators behave and adapt over time. I am aware the word “meme” was coined to rhyme with “gene”, and I don’t doubt you can find quotes where Dawkins ties them together directly, but I think that’s more for poetic or aesthetic considerations rather than because they are supposed to be analogous to genes specifically over and above other replicators.

    I actually see the whole meme idea as being more akin to the state of the original Darwinian theory, back before we could have all the objective metrics of genes we have now. And in *this* analogy, a meme is akin either to organisms (which replicate) or particular features or phenotypes (which replicate). The analogy is flexible because what is important to the idea is meme qua replicator rather than meme qua organism/phenotype/gene analogue.

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  7. BTW, in support of the idea that memes are not supposed to be analogous to genes specifically, I direct you to Robin’s quote above where memes are rather considered to be analogous to parasites or symbionts.

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  8. DM, agreed with your last comment. That’s why I said that “earworms,” because of being based on the cultural creation called music, might be a good reference for cultural issues.

    On Dawkins, it appears a bit of trying to have one’s cake and eat it. The name “meme” was clearly used by Dawkins not just for its reference to the Greek word for memory, but, IIRC, he specifically mentioned it as playing off the word “gene” as well, when he rolled out the word.

    That said, parasites and symbionts undergo biological evolution just like other critters.

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  9. > he specifically mentioned it as playing off the word “gene”

    Oh yes, the word is *definitely* a play on gene, because gene is another well-known replicator.

    I’m just saying the idea is not specifically tied to genes. The analogy holds to any replicator.

    > That said, parasites and symbionts undergo biological evolution just like other critters.

    Of course! All replicators evolve (given differential success in replication, variation, heredity, yadda yadda yadda).

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  10. Hi Socratic,

    Coel: Error rate isn’t an issue, if there were memes, as long as the error rate were low enough to ensure transmission of a meme were any amount higher than background noise.

    Well, there are indeed “memes”, and the propagation fidelity is indeed above the noise level, but it’s still a fairly limited concept since most memes morph too readily.

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  11. Oh, I agree on the morphing. And, this is where the non-Darwinian angle comes in. The cultural concept is often consciously changed by individuals or groups.

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  12. SocraticGadfly says, “Philip, on something like the culture of 7 billion humans, might not computer modeling hit Gödelian issues? Or any attempt to fully model human culture?”

    Interesting question, perhaps leading to super-Turing computing, unbounded nondeterministic computing, etc.

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  13. But, Philip, even nondeterministic computing should, I think be subject to Gödel. I believe the word “any” in “any sufficiently complex system” covers that, does it not?

    Of course, much that’s informally attributed to Gödel’s thinking is actually Tarski: https://en.wikipedia.org/wiki/Tarski%27s_undefinability_theorem

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  14. Socratic Gadfly, for that you might want a computer that can do Turing jumps: a true hypercomputer!

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  15. This might have been raised, but one difference between now and Darwin’s time is the realization that genes can transfer between species, such that it is become viewed as more of a network of life, rather than the original “tree of life.” Necessarily this is far more applicable to culture and while the “infection” analogy is valid, there is also the fact that our minds are designed to consume information, while infections seek to sneak in.
    The function of culture is to try to control the public effects of this consumption and direct people in prescribed ways. So a cultural infection would be one which seeks to override or break this control.

    We are constantly absorbing a range of input, but then digest it according to our needs, that suits the narrative of the culture. Otherwise the wheels start to come off and the culture will break apart.

    Linearity in a non-linear environment. Nodes and networks, feeding off one another.

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  16. Coel,

    “We do you care so much about the phrase “survival of the fittest” that you need to find some way in which it is non-tautological?”

    Hmm, sometimes I do get the feeling you read my essays for keywords to focus on, not for their actual arguments. 😉 I care because the current status of cultural evolutionary theory, in terms of Darwinism, is pretty much that of a tautology, since they lack a worked out functional ecology. Which, as I said multiple times, is not a problem for standard evobio, where there is such field, ever since Darwin, in fact.

    “The SEP entry on “fitness” ends with”

    Unfortunately I don’t have the time to read the entry now, but I note two things: i) it is co-autored by Alex Rosenberg, who is not an idiot (you’d like his Atheist Guide to Reality); ii) the ToC lists a number of issues that are, indeed, very much of “philosophical and biological urgency,” like individual vs group fitness, the propensity interpretation, the problem of individuality, and drift.

    DM,

    “Maybe not robustly, no. But I think we have a wishy-washy intuitive appreciation of how ideas compete and replicate and combine and so on”

    Well, if there is, I haven’t seen it. And it is worth noting not only that both Dawkins and Blackmore seem to have moved on from memetics, but that the only peer reviewed journal devoted to the field has folded years ago… I think memes are now just a common word for “cool and likely to go viral ideas,” but nothing more.

    brodix,

    “Maybe if we thought in terms of waves propagating, rather than particles replicating, memes would be more comprehensible”

    I don’t see how.

    Robin,

    “As a metaphor a meme is fine, as long as you don’t torture the metaphor.”

    Or try to turn it into a scientific theory.

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  17. i) it is co-autored by Alex Rosenberg, who is not an idiot (you’d like his Atheist Guide to Reality);

    Yes, I’d noticed that, and yes, since he is a scientistic atheist you’d expect me to agree with him (and yes, I do like that book 🙂 ). But I think he’s wrong in that article (he just seems to assume that the phrase SotF is central to Darwinism and so needs to be rescued somehow).

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  18. Massimo, I can understand that my assertion:
    “With some guidance from game theory, essentially all past and present moral norms are fairly easily revealed to be elements of cooperation strategies”
    does appear from your perspective to be a “bold claim that doesn’t square with the bewildering variety of moral norms.”

    However, through the lens of moral norms as cooperation strategies, the variety of past and present moral norms (meaning norms whose violators deserve punishment of at least reduced association) is not at all bewildering.

    Suggestions for counter-examples are always welcome. But I think you will find that, as suggested by game theory, all past and present moral norms fall first into subcategories advocating initiating cooperation (positive Golden Rule forms), maintaining cooperation (negative Golden Rule forms such as do not steal, lie, or kill), punishing immorality, and increasing the reliability of recognizing good cooperators by markers (such as male circumcision, food, dress, hair, prohibitions or other taboos) of membership and commitment to more cooperative sub-groups.

    These four universal sub-categories of moral norms are then almost infinitely further split into the diversity, contradictions, and bizarreness of culturally specific moral norms. Culturally specific moral norms differ in definitions of who is in favored in-groups and disfavored or even exploited out-groups, what markers of membership in in-groups and out-groups are used, the means of exploiting out-groups (such as claiming homosexuals are a threat to the in-group) to increase the benefits of cooperation in the in-group, the broadness of the application of heuristics such as “Do not kill”, and, as you suggest, the use of religion which can both standardize morality (which enhances cooperation on its own) and provides a supernatural source of detection, reward, and punishment of immoral behavior. Supernatural sources of detection and punishment of immoral behavior are especially valuable because they relieve the burden on the society, and on individuals, to detect and punish immorality which can be a tricky thing to get right.

    As described above, I am making a simple empirical claim. We might call it a bottom-up claim about the principle selection force for past and present enforced moral norms.

    We can also consider the claim from a top-down perspective. Assume there commonly exist large benefits of cooperation in our physical reality, particularly for intelligent beings. How can organisms reliably access these benefits in the long term? The benefits of cooperation selection force will almost certainly implement cooperation strategies first in biology – in a species’ version of a moral sense – and then in cultural moral norms. Thus we can reliably predict, knowing nothing about their biology or history, that the principle selection force for the morality of other intelligent species is also the benefits of cooperation in groups.

    So what does this have to do with the utility of understanding cultural norms as the product of evolutionary processes? Understanding cultural norms are the product of evolutionary processes leads directly to two useful insights.

    First, enforced moral norms (and the biology underlying our moral sense) share the same principle selection force – the benefits of cooperation in groups.

    Second, from the above top-down perspective, the benefits of cooperation in groups is almost certainly the primary selection force for enforced moral norms and the biology underlying a moral sense for all intelligent beings everywhere. That is, everywhere there commonly exist large benefits of cooperation.

    (Please note the definition of moral norms used above is only about norms whose violation is thought to deserve punishment. Norms such as those from virtue ethics whose violation do not deserve external punishment are in a different category of ethical norm that I might call “wisdom for living a good life”.)

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  19. Massimo,

    “I don’t see how.”

    It was just a passing thought I put up for comment.
    Much of what enters our mind, as light and sound, does so as waves and much of what sticks there, per Socratics earworms, does so rhythmically. Even physics talks about “beauty,” without really being sure of what they mean. So while it doesn’t fit the hard and precise forms the sciences prefer, when trying to describe memes, which could be everything from sports, to politics, to religious belief, to popular songs, when trying to figure out how it seeds our minds, detailed precision might not hold the key. In fact, “shut up and calculate” might just be another meme itself.

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  20. Massimo: “Sometimes”? 😉

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