Category Archives: Evolution


Culture shapes the evolution of cognition

A new paper, by Bill Thompson, Simon Kirby and Kenny Smith, has just appeared which contributes to everyone's favourite debate. The paper uses agent-based Bayesian models that incorporate learning, culture and evolution to make the claim that weak cognitive biases are enough to create population-wide effects, making a strong nativist position untenable.



A central debate in cognitive science concerns the nativist hypothesis, the proposal that universal features of behavior reflect a biologically determined cognitive substrate: For example, linguistic nativism proposes a domain-specific faculty of language that strongly constrains which languages can be learned. An evolutionary stance appears to provide support for linguistic nativism, because coordinated constraints on variation may facilitate communication and therefore be adaptive. However, language, like many other human behaviors, is underpinned by social learning and cultural transmission alongside biological evolution. We set out two models of these interactions, which show how culture can facilitate rapid biological adaptation yet rule out strong nativization. The amplifying effects of culture can allow weak cognitive biases to have significant population-level consequences, radically increasing the evolvability of weak, defeasible inductive biases; however, the emergence of a strong cultural universal does not imply, nor lead to, nor require, strong innate constraints. From this we must conclude, on evolutionary grounds, that the strong nativist hypothesis for language is false. More generally, because such reciprocal interactions between cultural and biological evolution are not limited to language, nativist explanations for many behaviors should be reconsidered: Evolutionary reasoning shows how we can have cognitively driven behavioral universals and yet extreme plasticity at the level of the individual—if, and only if, we account for the human capacity to transmit knowledge culturally. Wherever culture is involved, weak cognitive biases rather than strong innate constraints should be the default assumption.


Two grants for PhD students in cultural evolution at Max Planck Institute (Jena)

The MPI for the Science of Human History is offering two grants for PhD students, starting 2016 (deadline for applications is March 21st, 2016).

The Minds and Traditions research group (“the Mint”), an Independent Max Planck Research Group at the Max Planck Institute for the Science of Human History in Jena (Germany) is offering two grants for two doctoral projects focusing on “cognitive science and cultural evolution of visual culture and graphic codes“.

Funding is available for four years (three years renewable twice for six months), starting in September 2016. The PhD students will be expected to take part in a research project devoted to the cognitive science and cultural evolution of graphic codes.

More details here.


An Inquiry into & a Critique of Dennett on Intentional Systems

A new working paper. Downloads HERE:

Abstract, contents, and introduction below:

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Abstract: Using his so-called intentional stance, Dennett has identified so-called “free-floating rationales” in a broad class of biological phenomena. The term, however, is redundant on the pattern of objects and actions to which it applies and using it has the effect of reifying the pattern in a peculiar way. The intentional stance is itself a pattern of wide applicability. However, in a broader epistemological view, it turns out that we are pattern-seeking creatures and that phenomenon identified with some pattern must be verified by other techniques. The intentional stance deserves no special privilege in this respect. Finally, it is suggested that the intentional stance may get its intellectual power from the neuro-mental machinery it recruits and not from any special class of phenomena it picks out in the world.


Introduction: Reverse Engineering Dan Dennett 2
Dennett's Astonishing Hypothesis: We’re Symbionts! – Apes with infected brains 6
In Search of Dennett’s Free-Floating Rationales 9
Dan Dennett on Patterns (and Ontology) 14
Dan Dennett, “Everybody talks that way” – Or How We Think 20

Introduction: Reverse Engineering Dan Dennett

I find Dennett puzzling. Two recent back-to-back videos illustrate that puzzle. One is a version of what seems to have become his standard lecture on cultural evolution, this time entitled

As such it has the same faults I identify in the lecture that occasioned the first post in this collection, Dennett's Astonishing Hypothesis: We’re Symbionts! – Apes with infected brains. It’s got a collection of nicely curated examples of mostly biological phenomenon which Dennett crafts into an account of cultural evolution though energetic hand-waving and tap-dancing.
And then we have a somewhat shorter video that is a question and answer session following the first:

I like much of what Dennett says in this video; I think he’s right on those issues.

What happened between the first and second video? For whatever reason, no one asked him about the material in the lecture he’d just given. They asked him about philosophy of mind and about AI. Thus, for example, I agree with him that The Singularity is not going to happen anytime soon, and likely not ever. Getting enough raw computing power is not the issue. Organizing it is, and as yet we know very little about that. Similarly I agree with him that the so-called “hard problem” of consciousness is a non-issue.

How is it that one set of remarks is a bunch of interesting examples held together by smoke and mirrors while the other set of remarks is cogent and substantially correct? I think these two sets of remarks require different kinds of thinking. The second set involve philosophical analysis, and, after all Dennett is a philosopher more or less in the tradition of 20th century Anglo-American analytic philosophy. But that first set of remarks, about cultural evolution, is about constructing a theory. It requires what I called speculative engineering in the preface to my book on music, Beethoven’s Anvil. On the face of it, Dennett is not much of an engineer.

And now things get really interesting. Consider this remark from a 1994 article [1] in which Dennett gives an overview of this thinking up to that time (p. 239):

My theory of content is functionalist […]: all attributions of content are founded on an appreciation of the functional roles of the items in question in the biological economy of the organism (or the engineering of the robot). This is a specifically 'teleological' notion of function (not the notion of a mathematical function or of a mere 'causal role', as suggested by David LEWIS and others). It is the concept of function that is ubiquitous in engineering, in the design of artefacts, but also in biology. (It is only slowly dawning on philosophers of science that biology is not a science like physics, in which one should strive to find 'laws of nature', but a species of engineering: the analysis, by 'reverse engineering', of the found artefacts of nature - which are composed of thousands of deliciously complicated gadgets, yoked together opportunistically but elegantly into robust, self-protective systems.)

I am entirely in agreement with his emphasis on engineering. Biological thinking is “a species of engineering.” And so is cognitive science and certainly the study of culture and its evolution.

Earlier in that article Dennett had this to say (p. 236):

It is clear to me how I came by my renegade vision of the order of dependence: as a graduate student at Oxford, I developed a deep distrust of the methods I saw other philosophers employing, and decided that before I could trust any of my intuitions about the mind, I had to figure out how the brain could possibly accomplish the mind's work. I knew next to nothing about the relevant science, but I had always been fascinated with how things worked - clocks, engines, magic tricks. (In fact, had I not been raised in a dyed-in-the-wool 'arts and humanities' academic family, I probably would have become an engineer, but this option would never have occurred to anyone in our family.)

My reaction to that last remark, that parenthesis, was something like: Coulda’ fooled me! For I had been thinking that an engineering sensibility is what was missing in Dennett’s discussions of culture. He didn’t seem to have a very deep sense of structure and construction, of, well, you know, how design works. And here he is telling us he coulda’ been an engineer.

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Future tense and saving money: no correlation when controlling for cultural evolution

This week our paper on future tense and saving money is published (Roberts, Winters & Chen, 2015).  In this paper we test a previous claim by Keith Chen about whether the language people speak influences their economic decisions (see Chen's TED talk here or paper).  We find that at least part of the previous study's claims are not robust to controlling for historical relationships between cultures. We suggest that large-scale cross-cultural patterns should always take cultural history into account.

Does language influence the way we think?

There is a longstanding debate about whether the constraints of the languages we speak influence the way we behave. In 2012, Keith Chen discovered a correlation between the way a language allows people to talk about future events and their economic decisions: speakers of languages which make an obligatory grammatical distinction between the present and the future are less likely to save money.

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Dan Dennett on Patterns (and Ontology)

I want to look at what Dennett has to say about patterns because 1) I introduced the term in my previous discussion, In Search of Dennett’s Free-Floating Rationales [1], and 2) it is interesting for what it says about his philosophy generally.

You’ll recall that, in that earlier discussion, I pointed out talk of “free-floating rationales” (FFRs) was authorized by the presence of a certain state of affairs, a certain pattern of relationships among, in Dennett’s particular example, an adult bird, (vulnerable) chicks, and a predator. Does postulating talk of FFRs add anything to the pattern? Does it make anything more predictable? No. Those FFRs are entirely redundant upon the pattern that authorizes them. By Occam’s Razor, they’re unnecessary.

With that, let’s take a quick look at Dennett’s treatment of the role of patterns in his philosophy. First I quote some passages from Dennett, with a bit of commentary, and then I make a few remarks on my somewhat different treatment of patterns. In a third post I’ll be talking about the computational capacities of the mind/brain.

Patterns and the Intentional Stance

Let’s start with a very useful piece Dennett wrote in 1994, “Self-Portrait” [2] – incidentally, I found this quite useful in getting a better sense of what Dennett’s up to. As the title suggests, it’s his account of his intellectual concerns up to that point (his intellectual life goes back to the early 1960s at Harvard and then later at Oxford). The piece doesn’t contain technical arguments for his positions, but rather states what they were and gives their context in his evolving system of thought. For my purposes in this inquiry that’s fine.

He begins by noting, “the two main topics in the philosophy of mind are CONTENT and CONSCIOUSNESS” (p. 236). Intentionality belongs to the theory of content. It was and I presume still is Dennett’s view that the theory of intentionality/content is the more fundamental of the two. Later on he explains that (p. 239):

... I introduced the idea that an intentional system was, by definition, anything that was amenable to analysis by a certain tactic, which I called the intentional stance. This is the tactic of interpreting an entity by adopting the presupposition that it is an approximation of the ideal of an optimally designed (i.e. rational) self-regarding agent. No attempt is made to confirm or disconfirm this presupposition, nor is it necessary to try to specify, in advance of specific analyses, wherein consists RATIONALITY. Rather, the presupposition provides leverage for generating specific predictions of behaviour, via defeasible hypotheses about the content of the control states of the entity.

This represents a position Dennett will call “mild realism” later in the article. We’ll return to that in a bit. But at the moment I want to continue just a bit later on p. 239:

In particular, I have held that since any attributions of function necessarily invoke optimality or rationality assumptions, the attributions of intentionality that depend on them are interpretations of the phenomena - a ‘heuristic overlay’ (1969), describing an inescapably idealized ‘real pattern’ (1991d). Like such abstracta as centres of gravity and parallelograms of force, the BELIEFS and DESIRES posited by the highest stance have no independent and concrete existence, and since this is the case, there would be no deeper facts that could settle the issue if - most improbably - rival intentional interpretations arose that did equally well at rationalizing the history of behaviour of an entity.

Hence his interest in patterns. When one adopts the intentional stance (or the design stance, or the physical stance) one is looking for characteristic patterns. Continue reading


In Search of Dennett’s Free-Floating Rationales

I’ve decided to take a closer look at Dennett’s notion of free-floating rationale. It strikes me as being an unhelpful reification, but explaining just why that is has turned out to be a tricky matter. First I’ll look at a passage from a recent article, “The Evolution of Reasons” [1], and then go back three decades to a major exposition of the intentional stance as applied to animal behavior [2]. I’ll conclude with some hints about metaphysics.

On the whole I’m inclined to think of free-floating rationale as a poor solution to a deep problem. It’s not clear to me what a good solution would be, though I’ve got some suggestions as to how that might go.

Evolving Reasons

Dennett opens his inquiry by distinguishing between “a process narrative that explains the phenomenon without saying it is for anything” and an account that provides “a reason–a proper telic reason” (p. 50). The former is what he calls a how come? account and the latter is a what for? account. After reminding us of Aristotle’s somewhat similar four causes Dennett gets down to it: “Evolution by natural selection starts with how come and arrives at what for. We start with a lifeless world in which there are lots of causes but no reasons, no purposes at all.” (p. 50).

Those free-floating rationales are a particular kind of what for. He introduces the term on page 54:

So there were reasons before there were reason representers. The reasons tracked by evolution I have called “free-floating rationales” (1983, 1995, and elseswhere), a term that has apparently jangled the nerves of more than a few thinkers, who suspect I am conjuring up ghosts of some sort. Free-floating rationales are no more ghostly or problematic than numbers or centers of gravity. There were nine planets before people invented ways of articulating arithmetic, and asteroids had centers of gravity before there were physicists to dream up the idea and calculate with it. I am not relenting; instead, I am hoping here to calm their fears and convince them that we should all be happy to speak of the reasons uncovered by evolution before they were ever expressed or represented by human investigators or any other minds.

That is, just as there is no mystery about the relationship between numbers and planets, or between centers of gravity and asteroids, so there is no mystery about the relationship between free-floating rationales and X.

What sorts of things can we substitute for X? That’s what’s tricky. It turns out those things aren’t physically connected objects. Those things are patterns of interaction among physically connected objects.

Before taking a look at those patterns (in the next section), let’s consider another passage from this article (p. 54):

Natural selection is thus an automatic reason finder that “discovers,” “endorses,” and “focuses” reasons over many generations. The scare quotes are to remind us that natural selection doesn’t have a mind, doesn’t itself have reasons, but is nevertheless competent to perform this “task” of design refinement. This is competence without comprehension.

That’s where Dennett is going, “competence without comprehension” – a recent mantra of his.

It is characteristic of Dennett’s intentional stance that it authorizes the use of intentional language, such as “discovers,” “endorses,” and “focuses”. That’s what it’s for, to allow the use of such language in situations where it comes naturally and easily. What’s not clear to me is whether or not one is supposed to treat it as a heuristic device that leads to non-intentional accounts. Clearly intentional talk about “selfish” genes is to be cashed out in non-intentional talk, and that would seem to be the case with natural selection in general.

But it is one thing to talk about cashing out intentional talk in a more suitable explanatory lingo. It’s something else to actually do so. Dennett’s been talking about free-floating rationales for decades, but hasn’t yet, so far as I know, proposed a way of getting rid of that bit of intentional talk. Continue reading


Dennett's Astonishing Hypothesis: We're Symbionts! – Apes with infected brains

It's hard to know the proper attitude to take toward this idea. Daniel Dennett, after all, is a brilliant and much honored thinker. But I can't take the idea seriously. He's running on fumes. The noises he makes are those of engine failure, not forward motion.

At around 53:00 into this video ("Cultural Evolution and the Architecture of Human Minds") he tells us that human culture is the "second great endosymbiotic revolution" in the history of life on earth, and, he assures us, he means the "literally." The first endosymbiotic revolution, of course, was the emergence of eukaryotic cells from the pairwise incorporation of one prokaryote within another. The couple then operated as a single organism and of course reproduced as such.

At 53:13 he informs us:

In other words we are apes with infected brains. Our brains have been invaded by evolving symbionts which have then rearranged our brains, harnessing them to do work that no other brain can do. How did these brilliant invaders do this? Do they reason themselves? No, they're stupid, they're clueless. But they have talents the permit them to redesign human brains and turn them into human minds. [...] Cultural evolution evolved virtual machines which can then be installed on the chaotic hardware of all those neurons.

Dennett is, of course, talking about memes. Apes and memes hooked up and we're the result.

In the case of the eukaryotic revolution the prokaryots that merged had evolved independently and prior to the merging. Did the memes evolve independently and prior to hooking up with us? If so, do we know where and how this happened? Did they come from meme wells in East Africa? Dennett doesn't get around to explaining that in this lecture as he'd run out of time. But I'm not holding my breath until he coughs up an account.

But I'm wondering if he's yet figured out how many memes can dance on the head of a pin.

More seriously, how is it that he's unable to see how silly this is? What is his system of thought like that such thoughts are acceptable? Continue reading


Underwood and Sellers 2015: Beyond narrative we have simulation

It is one thing to use computers to crunch data. It’s something else to use computers to simulate a phenomenon. Simulation is common in many disciplines, including physics, sociology, biology, engineering, and computer graphics (CGI special effects generally involve simulation of the underlying physical phenomena). Could we simulate large-scale literary processes?

In principal, of course. Why not? In practice, not yet. To be sure, I’ve seen the possibility mentioned here and there, and I’ve seen an example or two. But it’s not something many are thinking about, much less doing.

Nonetheless, as I was thinking about How Quickly Do Literary Standards Change? (Underwood and Sellers 2015) I found myself thinking about simulation. The object of such a simulation would be to demonstrate the principle result of that work, as illustrated in this figure:

19C Direction

Each dot, regardless of color or shape, represents the position of a volume of poetry in a one-dimensional abstraction over 3200 dimensional space – though that’s not how Underwood and Sellers explain it (for further remarks see “Drifting in Space” in my post, Underwood and Sellers 2015: Cosmic Background Radiation, an Aesthetic Realm, and the Direction of 19thC Poetic Diction). The trend line indicates that poetry is shifting in that space along a uniform direction over the course of the 19th century. Thus there seems to be a large-scale direction to that literary system. Could we create a simulation that achieves that result through ‘local’ means, without building a telos into the system?

The only way to find out would be to construct such a system. I’m not in a position to do that, but I can offer some remarks about how we might go about doing it.

* * * * *

I note that this post began as something I figured I could knock out in two or three afternoons. We’ve got a bunch of texts, a bunch of people, and the people choose to read texts, cycle after cycle after cycle. How complicated could it be to make a sketch of that? Pretty complicated.

What follows is no more than a sketch. There’s a bunch of places where I could say more and more places where things need to be said, but I don’t know how to say them. Still, if I can get this far in the course of a week or so, others can certainly take it further. It’s by no means a proof of concept, but it’s enough to convince me that at some time in the future we will be running simulations of large scale literary processes.

I don’t know whether or not I would create such a simulation given a budget and appropriate collaborators. But I’m inclined to think that, if not now, then within the next ten years we’re going to have to attempt something like this, if for no other reason than to see whether or not it can tell us anything at all. The fact is, at some point, simulation is the only way we’re going to get a feel for the dynamics of literary process.

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It’s a long way through this post, almost 5000 words. I begin with a quick look at an overall approach to simulating a literary system. Then I add some details, starting with stand-ins (simulations of) texts and people. Next we have processes involving those objects. That’s the basic simulation, but it’s not the end of my post. I have some discussion of things we might do with this system followed with suggestions about extending it. I conclude with a short discussion of the E-word. Continue reading


Could Heart of Darkness have been published in 1813? – a digression from Underwood and Sellers 2015

Here I’m just thinking out loud. I want to play around a bit.

Conrad’s Heart of Darkness is well within the 1820-1919 time span covered by Underwood and Sellers in How Quickly Do Literary Standards Change?, while Austen’s Pride and Prejudice, published in 1813, is a bit before. And both are novels, while Underwood and Sellers wrote about poetry. But these are incidental matters. My purpose is to think about literary history and the direction of cultural change, which is front and center in their inquiry. But I want to think about that topic in a hypothetical mode that is quite different from their mode of inquiry.

So, how likely is it that a book like Heart of Darkness would have been published in the second decade of the 19th century, when Pride and Prejudice was published? A lot, obviously, hangs on that word “like”. For the purposes of this post likeness means similar in the sense that Matt Jockers defined in Chapter 9 of Macroanalysis. For all I know, such a book may well have been published; if so, I’d like to see it. But I’m going to proceed on the assumption that such a book doesn’t exist.

The question I’m asking is about whether or not the literary system operates in such a way that such a book is very unlikely to have been written. If that is so, then what happened that the literary system was able to produce such a book almost a century later?

What characteristics of Heart of Darkness would have made it unlikely/impossible to publish such a book in 1813? For one thing, it involved a steamship, and steamships didn’t exist at that time. This strikes me as a superficial matter given the existence of ships of all kinds and their extensive use for transport on rivers, canals, lakes, and oceans.

Another superficial impediment is the fact that Heart is set in the Belgian Congo, but the Congo hadn’t been colonized until the last quarter of the century. European colonialism was quite extensive by that time, and much of it was quite brutal. So far as I know, the British novel in the early 19th century did not concern itself with the brutality of colonialism. Why not? Correlatively, the British novel of the time was very much interested in courtship and marriage, topics not central to Heart, but not entirely absent either.

The world is a rich and complicated affair, bursting with stories of all kinds. But some kinds of stories are more salient in a given tradition than others. What determines the salience of a given story and what drives changes in salience over time? What had happened that colonial brutality had become highly salient at the turn of the 20th century? Continue reading


Underwood and Sellers 2015: Beyond Whig History to Evolutionary Thinking

In the middle of their most interesting and challenging paper, How Quickly Do Literary Standards Change?, Underwood and Sellers have two paragraphs in which they raise the specter of Whig history and banish it. In the process they take some gratuitous swipes at Darwin and Lamarck and, by implication, at the idea that evolutionary thinking can be of benefit to literary history. I find these two paragraphs confused and confusing and so feel a need to comment on them.

Here’s what I’m doing: First, I present those two paragraphs in full, without interruption. That’s so you can get a sense of how their thought hangs together. Second, and the bulk of this post, I repeat those two paragraphs, in full, but this time with inserted commentary. Finally, I conclude with some remarks on evolutionary thinking in the study of culture.

Beware of Whig History

By this point in their text Underwood and Sellers have presented their evidence and their basic, albeit unexpected finding, that change in English-language poetry from 1820-1919 is continuous and in the direction of standards implicit in the choices made by 14 selective periodicals. They’ve even offered a generalization that they think may well extend beyond the period they’ve examined (p. 19): “Diachronic change across any given period tends to recapitulate the period’s synchronic axis of distinction.” While I may get around to discussing that hypothesis – which I like – in another post, we can set it aside for the moment.

I’m interested in two paragraphs they write in the course of showing how difficult it will be to tease a causal model out of their evidence. Those paragraphs are about Whig history. Here they are in full and without interruption (pp. 20-21):

Nor do we actually need a causal explanation of this phenomenon to see that it could have far-reaching consequences for literary history. The model we’ve presented here already suggests that some things we’ve tended to describe as rejections of tradition — modernist insistence on the concrete image, for instance — might better be explained as continuations of a long-term trend, guided by established standards. Of course, stable long-term trends also raise the specter of Whig history. If it’s true that diachronic trends parallel synchronic principles of judgment, then literary historians are confronted with material that has already, so to speak, made a teleological argument about itself. It could become tempting to draw Lamarckian inferences — as if Keats’s sensuous precision and disillusionment had been trying to become Swinburne all along.

We hope readers will remain wary of metaphors that present historically contingent standards as an impersonal process of adaptation. We don’t see any evidence yet for analogies to either Darwin or Lamarck, and we’ve insisted on the difficulty of tracing causality exactly to forestall those analogies. On the other hand, literary history is not a blank canvas that acquires historical self-consciousness only when retrospective observers touch a brush to it. It’s already full of historical observers. Writing and reviewing are evaluative activities already informed by ideas about “where we’ve been” and “where we ought to be headed.” If individual writers are already historical agents, then perhaps the system of interaction between writers, readers, and reviewers also tends to establish a resonance between (implicit, collective) evaluative opinions and directions of change. If that turns out to be true, we would still be free to reject a Whiggish interpretation, by refusing to endorse the standards that happen to have guided a trend. We may even be able to use predictive models to show how the actual path of literary history swerved away from a straight line. (It’s possible to extrapolate a model of nineteenth-century reception into the twentieth, for instance, and then describe how actual twentieth-century reception diverged from those predictions.) But we can’t strike a blow against Whig history simply by averting our eyes from continuity. The evidence we’re seeing here suggests that literary- historical trends do turn out to be relatively coherent over long timelines.

I agree with those last two sentences. It’s how Underwood and Sellers get there that has me a bit puzzled. Continue reading