Barbara Finlay has a lot to say about Evolutionary Psychology. As Co-Editor of the premier journal Behavioral and Brain Sciences (BBS), she knows the publishing trends. As a comparative brain anatomist, she can evaluate the concept of evolved special-purpose modules. And she has her own intriguing hypothesis about a specialized human adaptation that she calls the Pain of Altruism. This makes her the perfect person to conclude This View of Life’s series of articles titled “What’s Wrong (and Right) about Evolutionary Psychology”.

I interviewed Barb in her office during the summer of 2015.

DSW: Barbara Finlay, welcome to This View Of Life

BF: Glad to be here!

DSW: This interview will be part of a series of pieces on Evolutionary Psychology and I’m excited to talk with you for three reasons. First, you are editor of Behavioral and Brain Sciences, which is a landmark journal. Second, your own work on comparative brain anatomy, which causes you to be critical not just of Evolutionary Psychology but also what you call human exceptionalism.  And third, a particular hypothesis that you have proposed called “The Pain of Altruism.” So, why don’t we launch right into it? Tell us about your background first, a little about your academic training and where you came from.

BF: I got my PhD at MIT after getting my bachelor’s in the most polar opposite place you could imagine, Oberlin College. I was inspired by [David H.] Hubel and [Torsten] Wiesel, who were the first people reporting on the visual cortex. I ended up working on the visual cortex with Peter Schiller at MIT.  After about 12-15 months, when we hadn’t discovered how vision worked, I became impatient. I guess that’s what you get to do as a grad student.  A lot of people were impatient. It was a depressing period. People thought we would put electrodes into the head and see how vision worked.

DSW: But it proved to be way more complicated.

BF: Yes, that’s true. Then I switched over to doing developmental neurobiology, looking at how the visual system was constructed, which is a somewhat more tractable question. I was at MIT a bit less than 4 years, came right to Cornell as professor, knowing rather little, and started to teach. Fortunately,  Glenn Northcutt, a very famous comparative neuro-anatomist from UCSD, showed up for a workshop during my third year here and convinced me that the way to go would be what would be presently called evo-devo, about how development evolved to produce different systems. Evolution could be the basis of understanding development and vice versa. I’ve been working on that ever since, but it didn’t get called Evo-Devo until 25-30 years later.

DSW: When did the term Evo-Devo come about? The late 80s?

BF: more like ’95.

DSW: The question of how Evo-Devo could be new in the 1990s–there’s a story behind that. So now tell us about the journal, Behavioral and Brain Sciences. It has a special status among academic journals.

BF: BBS was founded by Stevan Harnad back in the 70s and it was a unique journal from the start. It modeled itself on an anthropology journal, which was a target article and commentary…

DSW: Current Anthropology?

BF: Yes, but he expanded that considerably. What we look for in BBS, what has always been the key thing, is a target article that has a strong and coherent thesis–that is, an argument of some kind–about how to look at something, what’s the best way to organize empirical data in some domain of inquiry, something to that effect. We distinguish the argument-centered approach from a review paper, where the author’s goal is focused on accumulating and organizing.

DSW: Something a little more groundbreaking.

BF: Groundbreaking is good! You know, novel. We don’t go for controversy per se but these articles just normally generate controversy because they are chosen to be strong points of view. We try to look for arguments that are not hopelessly detailed in their number of postulates.

DSW: A big picture.

BF: Although at the same time, we’re really discouraging of papers that are “my theory of consciousness that I thought up last week in my garret” or things that aren’t heavily empirically supported, no matter how brilliant they might be. So it’s an unusual combination of a strong thesis and a lot of empirical grounding.

DSW: I’ve had two target articles in BBS so I can testify that the review process is grueling–probably the most grueling review process of any academic journal I know. How many reviewers do you send it out to?

BF: We’ve pared it down considerably. I was stunned when Stevan Harnad was training me back in 2001 that he truly wanted to get 10-12 reviews for each article. Both Paul Bloom, my co-editor, and I thought  that in the current workload climate, 10-12 are just plain excessive, so we go for 4-6.

DSW: That’s still more than most.

BF: That’s 3x more than most, and not only that, because of the length of the target articles, which will run up to 70 or so pages– 12,000 to 14, 000 word–the reviews tend to be long as well.

DSW: Any conscientious review would have to be.

BF: And we don’t send all that many out, just because it is so taxing.

DSW: Then there’s the process of getting commentaries. There is a solicitation process, a review process, and you end up with about two dozen commentaries for every target article. So thanks to all that work, BBS is ranked #1 among behavioral science journals and right up there among brain journals.

BF: Yes, and we want to underline too that for organizations that are doing citation counts for impact, the commentaries do not count as citations.

DSW: It’s only the target article, so you’re not padding it.

BF: I think the process itself naturally amplifies the number of citations that an article is guaranteed– 25 people [the commentators] have already read your article closely. When does that [otherwise] happen?

DSW: Yes, that’s right! That’s what an impact factor of 25 is! So that makes BBS an interesting microcosm for studying the behavioral sciences from an evolutionary perspective. A while back, I did a survey of BBS. I was in the process of writing a grant proposal for NSF. The first thing I did was look at articles – I think it was between 2000 and 2004, so just when you were coming on – to see the proportion of target articles that were written from an evolutionary perspective. That proportion turned out to be about 30% and I wanted that number to show that the behavioral sciences are starting to be approached from an evolutionary perspective. This was not fringe science, this was not pseudo science –- if were, it wouldn’t get into BBS. So that was an interesting number. Then I contacted those authors and I found out about their background. What that showed is that the majority of the authors had not been trained in evolutionary theory – this will not surprise you – they had been trained in some other field and they picked up their knowledge of evolution.

BF: Neither of the editors have been trained in evolution either.

DSW: There you go! The proposal was to fund EvoS, our campus-wide evolutionary studies program, at Binghamton and a sister program at New Paltz, because what’s happening at the level of research is not yet reflected in higher education. That survey was very helpful, we got the grant proposal, and EvoS is a thriving consortium of programs. Against that background, I would like you to share your experience as editor of BBS and the extent to which the articles are incorporating a modern evolutionary perspective– and if it’s changed over the years, because you have 14 years of experience to reflect upon.

BF: Yes, I think I’ve been sitting in the middle of perhaps the largest change. Before I came, there were many notable articles in that domain–your original one, for example1, and David Buss’s article on men’s versus women’s preferred mates2, cross-culturally–things of that kind. I wrote one myself on brain evolution3. I think that around 2000-2005, evolutionary psychology had been established as a particular school of thought…

DSW: Just to put dates on that, the term was coined in the late 1980s. In 1992 the landmark book came out, The Adapted Mind, which really put that school of thought on the map.

BF: Evolutionary Psychology articles tend to be the kind of argument-centered article, not in content but in style, that BBS tends to look for. It is often a thesis about males and females.

DSW: It’s got the big picture part.

BF: We get a lot of Evolutionary Psychology submissions, perhaps too many, I think , given the absolute representation across the entire domain of psychology. There was no other kind of evolution in psychology, because for years, psychology, particularly in its social aspects, had renounced evolution or genetics as a causal explanation–period. Evolution wasn’t included in any kind of definition. The objection was that evolution was too determinist, and quite rightly. At that time, the modern synthesis in evolutionary biology was dominating, and in my view the most interesting human behaviors — altruistic behavior, going to war, religions – were ones that the modern synthesis’ genetically-based evolutionary biology could not even hope to address.

DSW: Right, so if I can just play that back–In my interview with Eva Jablonka, she dwells upon this quite a lot. The study of evolution became highly gene-centric and so therefore gave up the explanatory ability to explain all these cultural things. In some ways, the culture and behavior folks seceded on their own, but in other ways, evolutionary theory went off in a direction that had little to offer for those topic areas.

BF: So the first thing I noticed, I think, was Herb Gintis’s paper4 on changing viewpoints in sociobiology and how it was time to rethink the nature of the presumed genetic account of behavior– time for the social sciences to start taking biology seriously and time for biology to …

DSW: That was centered a lot on game theory, and so very much steered itself in the direction of social behavior. The evolution of cooperation and that sort of thing.

BF: Starting about that time and ramping up to the present, we are now faced with a true glut of cultural evolution manuscripts.

DSW: That’s really interesting.

BF: I would say that cultural evolution has now replaced consciousness as the number one unsolicited topic.

DSW: I’m very happy to hear that!

BF: Since we need to cover all of cognitive science and anthropology and computation and so forth, we’re forced to become more selective, so we’re having to cut. Paul Bloom and I, dividing decisions between the two of us,  cannot coordinate perfectly, so we over-admitted the total percent of cultural evolution manuscripts and might have to pull back.

DSW: One of your most recent acceptances, by John Gowdy and Lisi Krall, is on human economies as super organisms, so how cool is that!

BF: Yes, we’re getting all sorts of things. These papers are all so interesting! We’re right on the uptick of a whole new discipline being discovered, but nevertheless we have to pay some attention to people in perception and computation.

DSW: Right. Next I want to explore the distinction between what could be called “narrow school” and “broad school” Evolutionary Psychology.  Broad school is the study of psychology from an evolutionary perspective and narrow school is the school of thought that originated in the late 1980s and took on that name. You were at a workshop at Cornell that I was speaking at, which I have written about. A question about Evolutionary Psychology was asked from an audience member and every speaker at the workshop other than myself rolled their eyes and tried to distance themselves from EP. What’s your take on that?

BF: EP is an unusually strict concatenation of highly charged concepts. First, the idea that cognition and lots of behavior is best thought of as a bunch of modular separate organs that can be selected independently–the Tooby and Cosmides version of EP–  second, that a lot of current behavior can be explained by what original adaptations were for, the environment of evolutionary adaptiveness … well, I don’t want to list every…

DSW: you listed the two most important.

BF: Those two things run so hard against the main two tenets of the research I’ve done and also the department I’m embedded in…

DSW: That’s a good segue, to your own work, so why don’t we just go there.

BF: Inspired originally by Northcutt, I set the question for myself of how you get a anatomically-distributed system  in the brain like the visual or olfactory system to get relatively bigger.  Suppose a species moved into a nocturnal niche, and would do better to rely on olfaction than vision, and should thus expend more processing on the sense of smell.  But olfaction is not just the nose, or a single brain part, there are parts distributed throughout the brain —how would you coordinate that? I was first interested in cell death as a way of sculpting out such functional systems in development.  Then I looked at the generation of neurons to see if the numbers in groups of neurons in different anatomical locations, but representing a single functional system, were in some way coordinated.  Essentially I was looking for modules that could be selected by evolution, and boy, did I not find any! Instead, to my complete surprise, both at the level of describing adult nervous systems  from various species, and neural development in the same animals, everything was predictable from brain size.  If I divided the brain into the parts that anatomists like and looked at twelve different parts that all together added up to the whole brain, and then asked how well I can predict the size of those particular parts from the size of the whole, the answer was, with 96% accuracy, you can do that. In other words, if you know the size of the whole brain, you know the size of the midbrain, the thalamus, the cortex.  Then you add in a couple–and I mean a  very few -of correction factors, such as the cortex is bigger in primates overall, you reach 99% accuracy.   For example, the human cortex is exactly the size it should be for a primate with a brain that’s overall as big as ours. Then I started to look within that for functional systems, such as the visual system. Parts within functional systems also scale predictably with respect to overall brain size. It’s important to realize that the scaling isn’t linear, but allometric. For example, the cortex gets to be an increasingly large proportion of brain size as size increases in any mammalian group. , and the human cortex  is just where it should be for primates. The cortex can go from about 20 percent to 80 percent of volume, say, between rodents and primates, increasing sharply but very predictably.

DSW: Let me stop you there. I’m familiar with this through your work, but when I first encountered it…

BF: It takes a while…

DSW: …it does take a while, and it leaves a lot of questions unresolved. One of my favorite books is the Scientific American book titled Evolving Brains by John Allman, which seemed at least when I read it to tell a different story–that when you look at electric fish or some species where olfaction is the primary sensory mode, then this was reflected in brain proportion. Is that not correct?

BF: No, both accounts are true. If you know just brain size you get at 96 percent of the variance—and I’m talking about just mammals now–but then the important 3-4 percent is the olfactory-limbic collection of structures that co-vary with the olfactory bulbs,  –the hippocampus and other olfactory cortices. You can have animals where those are particularly large, like rodents and anteaters, or where they’re small, as in primates. Or you can have both the cortex and the olfactory apparatus quite large, as in carnivores, so those things can sort independently5.

DSW: So, yes that happens but it accounts for a very small percent of the variance?

BF: Yeah, but it’s a big amount of tissue.

DSW: Right, functionally is what counts. Does that make your point about modularity less relevant? Are we right back where we started?

BF: The really remarkable thing is the stability of the nervous system compared to the instability of the periphery. You definitely can get new functions into old tissues and the interesting thing is how stable the fundamental anatomical organization of that tissue stays.  I was being careful to say before: “anatomically defined areas”, like the primary visual cortex.  We actually looked at the relative size of primary visual cortex in diurnal versus nocturnal mammals; we didn’t find any difference6. Does that mean that visual animals don’t devote more of their brains to vision? They certainly do.  How?  So for example, in deprivation situations, if a person is blind from birth, or simply not sighted voluntarily for only two weeks, they’ll start to use their visual cortex to read Braille7. We all impressed ourselves too much by calling the visual cortex the visual cortex, and then the idea naturally arose that if you want to make a visual animal the only thing you can do is make that visual cortex bigger. But if you can put vision in a lot of places…

DSW: I see! Aren’t there experiments where they rerouted the eyes to the olfactory cortex in ferrets?

BF: Yes, but it doesn’t happen evolutionarily.

DSW: But it shows the plasticity of the brain to be able to do that.

BF: This used to be an absolutely heretical thing to say. And boy, did I get a lot of crap for it. But it turns out that unbeknownst me the same thing was happening in evo-devo and the control of body plans…

DSW: OK, nice!

BF: …so what people were discovering when they were looking at gene expression and transcription factors, and so forth, that set up both the invertebrate and vertebrate body plan, the 11 initial segments that organize the body plan, that is, what’s front and back, middle and side were exactly the same for vertebrates and invertebrates organized by the exact same genes.  The expectation prior to that time was that evolution is a random walk, and that any part could be under selection, new parts could be selected as necessary.

DSW: These are developmental building blocks that are very conservative.

BF: Yes, and this was written about very nicely in Jon Gerhart and Marc Kirschner’s Cells, Embryos, and Evolution–one of my favorite books–about the conservation of fundamental mechanism, an observation keeps coming up over and over again. They identified a conserved body plan,  and  the same is true for the brain plan and for fundamental building blocks like oxidative metabolism.The number of neurotransmitters is a conserved set that you can count on two hands.

DSW: But we still have giraffes and anteaters and whales, so the phenotypic diversity hasn’t changed. We’ve learned some things about their development, and those things are surprising in some sense, but the conservative nature of those building blocks has not prevented the diversity that we see.

BF: Yes, so the point of this research is never to say “in fact, mice and humans are exactly the same”. We are not. The question is, what’s the palette of mechanisms that are allowed into a causal explanation of how you get diversity? When people first started thinking about it, they thought that in order to evolve language, a little chunk of tissue must be designated and committed to be language cortex, to get language input, and to do language related transformations within itself. Now, proposals like that seem much less plausible, since fundamental architecture is so conserved.  Now you’d be much more likely to offer an explanation about what information the organism gets early on, what it is motivated to do, and how we can understand language structure in terms of the rather rich variety of computational devices we know to be in every brain.

DSW: I can see that this is important. We can go through a number of specific hypothesis that are associated with Evolutionary Psychology. One is Robin Dunbar’s hypothesis that the larger the group size, the more the brain…can you state Dunbar’s hypothesis–because you can do it better than I can–and then critique it?

BF: Well, Dunbar’s had at least four theories about what a socially adapted brain might be. I think the fundamental thesis is unfalsifiable in a way. Social complexity is likely to be associated with a large brain. So is tool use, elaborate foraging strategies, and any number of different complex abilities–except, interestingly, migration and long-term wayfinding.

DSW: Why not?

BF: Shall I digress on that?

DSW: Sure.

BF: We tend to think of a goose following an elaborate route as doing an amazing cognitive calculation, but what that goose is doing is keeping itself from the harder task of being a chickadee and having to master 3 or 4 or 5 different environments. If you compare the animals who have evolved to follow their environment around, some of the structures involved with wayfinding are larger – but in general they’re more small-brained than the ones who have to be a winter kind of bird and then a spring kind of bird8,9.

DSW: Awesome! So you can be less variable by migrating.  I actually wrote a paper on that, in which specialization can evolve with habitat preference. If you can choose your habitat, then you experience a uniform environment, while a generalist has to cope with different environments.

BF: And Louis Lefebvre, who’s one of my favorite scientists in this whole domain, looked at a lot of capacities that are associated with large brains. A study that I cite all the time–so first off, all large-brained abilities co-vary, such as an ability to use tools, or innovate, or do well in laboratory tests of set shifting, and things like that8. Those all co-vary, but the real killer observation is that the bigger your relative brain size is, the more likely you are to succeed in invading a new territory9. Chickadees spread everywhere, turkeys not so much. Similarly, raccoons but not rabbits.

DSW: So many specific things can select for brain size but the way that happens is that the whole brain has to become bigger.

BF: Yes.

DSW: So therefore you get other capacities?

BF: You get the opportunities to combine all these different kinds of abilities and set them according to your immediate history. You’ve got four really big learning engines in your brain: two kinds of associators, a reinforcement system and an error correction system in the cerebellum.  Every species’ brain  has all those parts and every part all looks at all incoming information. What a developing animal is motivated to look at ends up as computations that are populating its nervous system,for generalist and specialist species.

DSW: Okay, so I want to nail this down. If Dunbar is correct in a sense, and if you have two primate species that differ in their social complexity, and you try to hold them the same in other respects, then their brains will be different, but how will they be different? Will one be bigger than the other?

BF: As to Dunbar… there are two arguments going on, and remember we’re talking about the details of 1 percent of the variance here, about whether there is any excess brain size to be accounted for in primates with large group sizes.  For the first argument, a technical, quantitative one, I’m with what I think is the most of researchers who say there isn’t any interesting “extra” brain to account for–it’s predictable from brain size10. Dunbar says there really is excess difference. Initially,  he looked at was plain old brain size. That was the first claim. Then, no, it’s relative brain size, and the last thing was no, it’s a particular chunk of the frontal temporal lobe. So the hypothesis has migrated around as to…

DSW: No shame! That’s what happens! Science progresses! Science progresses!

BF: But the trouble is that there’s no co-varying out of related abilities, the second , non-technical argument. First, the percentage of the variance is tiny, and what else varies in these animals? Do they have larger territories? Do they use tools more? Do they invade new regions more? Are they associated with a particular type of social structure? The list of things that are potential covariates is enormous–you could go on for the rest of the afternoon and I would bet my bottom dollar that we would find other aspects of complex behavior that are going to vary with any aspect of social complexity that you put up, just because the nature of the stuff that Louis Lefebvre has already demonstrated of complex behavioral abilities that intrinsically co-vary. And there’s no way that Dunbar would be able to, or should or could, remove the rest of cognition from social cognition in primates.

DSW: OK, so back to language. Back in the day with Steve Pinker and Noam Chomsky and others, the reasoning was that language is such a specialized adaptation that it had to be reflected by some kind of organ in the brain. This would be another part-by-part selection story and you’re saying “not true”—right?

BF: Yeah, and with a lot of evidence as well.  Morton Christensen down the hall here, works a lot on how language evolves to fit the brain and not the other way around and has a number of examples like that.

DSW: Does that mean, if I understand correctly, that different languages can be very different from each other, because historically they are outcomes of cultural evolution and the way a particular population crafts a language might be very different? There might not be a fundamental unity to different languages? Am I right about that?

BF: Yeah, it was really quite strange that…

DSW: A universal grammar is basically what’s being challenged.

BF: Yes—so the idea, and really without much data, was that there was in fact a universal grammar. On its first incarnation it was a great deal more detailed than it ended up becoming.  Universal grammar was a proposal, or a hypothesis, about English and some other closely associated languages. It was never an elaborate look for what the nature of the universal grammar might be, across the languages of whole world. It was data-free. If I might be permitted a sexist crack: one of tenets of Chomsky about why you had to have a universal grammar was “poverty of the stimulus.”  The idea was that no child could possibly learn language given the inferior descriptive information that any infant got. So, as I’m raising my son and chatting to him, and everybody else is chatting to him, I’m thinking “if this is poverty of the stimulus, I would like to see wealth of the stimulus!”

[lots of laughter]

DSW:  At the same time there has to be some scaffolding? That’s true with visual development too.

BF: What universal grammar eventually got moved down to was the ability to use symbols recursively, and not much more.  There’s nothing much linguistic about that at all, if anything. So there’s no candidate at this point that I’m aware of for something that’s really about language that is a feature of just human brains.

DSW: that’s amazing!

BF: It’s an empirical question, you could….

DSW: …amazing that there can be something that’s unique phenotypically-that’s beyond question—and yet not based on much that’s unique in the human brain.

When evolutionary psychologists talk about modularity, they start from the outside—in other words, phenotypic modularity. The point they make, that species have adaptations for their particular environments, is true, especially for non-human species. The phenotypic modules must be mechanistically instantiated in some way– sex differences for example, such as why men are more risk-taking than women. Or, to pick a very specific one, the last person I interviewed was Debra Lieberman. Her work examines how kin recognize each other with respect to incest avoidance and helping behavior. It’s a neat trick–to be adaptive, you have to avoid mating with your close relatives but you also need to help them. You have to be positively attracted to them in some sense and repelled by them in another, and how do you recognize a sibling anyway? She has shown, convincingly to me, that the recognition mechanism it is different for older siblings vs. younger siblings–based on the quality of information. If you‘re an older sibling and you have a younger sibling, you saw it born, you saw your mom nurse it, and that’s good information. If you’re a younger sibling, then you haven’t seen that for your older sibling and so the best information that you have is co-residence — how long have you been living with them. And, again convincingly, as far as I can tell, she shows that there’s a sort of if-then clause. Something happens inside the brain that makes sense from an evolutionary perspective, so it seems that natural selection has been fine tuned enough to evolve those very specific and context-sensitive recognition mechanisms. Now, no one would expect that to be reflected in brain size, and probably no one would expect to see some spot on the brain that does that, but something does that – a circuit? Or what? So the modularity thesis might be correct but we just have to look for it in the brain in the right way. What do you have to say about that?

BF: I would make exactly your argument. There has to be species- specific neural circuitry because of the x, y, and z kinds of evidence you just described,.  This circuit  might not be the little brain part I can draw a line around and say there’s the language area.   What we do need to figure out why it is that humans are so interested in learning language and chimps are so wildly uninterested–that’s where I would start. One of the most interesting things to me is, there is a lot of wired-in form recognition, from very basic to very structurally complicated. For a basic example, a loud noise will startle anyone– so that’s a lot of auditory processing that is responded to by orienting to the noise.  That’s innate–3D reaching in space and localizing things. That’s all wired in. There are certainly sex differences in activity levels and in many animals, different kinds of innate knowledge, like recognizing foods or some predators. I wrote a paper with Michael Anderson in “Frontiers” in 2013 about the relationship between neuroplasticity and evolution and cognition11. Whenever researchers first described species-specific behavior in neural terms, they wanted to go and find an encapsulated module that contained the motivation and the circuitry. So we come up with a noun for the behavior, we put the noun in the brain… We just have to get a better descriptive vocabulary for how to assemble new capacities out of old parts. Now where I’ve gone with that… I really think that researchers are coming to recognize a major location for evolutionary change in brains  and that’s the subcortical motivational and emotional systems. I think that monogamous voles were the greatest piece of explanatory evidence regarding human language that has come down the pike.

DSW: Why is that now?

BF: So, I don’t know if everyone knows…

DSW: You have to give some background–I promise you that not everyone will!

BF: So there are several species of  voles with different social systems. I always get the species all wrong and I apologize to my colleagues for that, so I leave the species names vague.  Most rodents and most mammals are promiscuous, not monogamous. A few species are socially monogamous, like ourselves. Some vole species that have separated themselves out from the promiscuous hoard and become monogamous. They have done that, not by installing a “this-is-my-husband-the-vole” recognizer in their primary visual cortex, but by a very specific alteration of their motivational system, tying individual recognition to motivation  12. This is what they’ve done.  Sex motivates all species; sex-related organization is found all through these subcortical systems.   What the monogamous voles have done is make a necessary connection between a particular animal and the reinforcement of sex. So, they’ve now plugged in their recognition of individual animals via oxytocin or vasopressin receptors into their primary reinforcement circuitry.

DSW: So only the special someone elicits the…?

BF: These voles will work to be with their partners and other animals will not.

Everyone is rewarded by sex–that’s the baseline and these animals continue to be rewarded by sex. They are not completely monogamous. But what does happen is that male and female pairs live together for an extended period of time and raise multiple litters, take care of the litters together, and by so doing, get better offspring survival rates for quintessential reproductive success. This is what the whole brain is about, basically – using the reinforcement circuitry to organize for what you will do and repeat doing. This particular system is changed in these animals and it’s done by just the addition of a very particular connection.  The interesting thing about this, compared to the predictability and stability of the whole brain neuron numbers and volumes, is that these neuromodulator systems are just churning around. There’s a lot of individual variability and between-species variability. You can turn a promiscuous vole, or mouse into a monogamous one by doing a genetic injection of these receptors in the correct place.  The late Jim Goodson of Indiana University, who did his doctoral and postdoctoral work here at Cornell  did a lot of similar work extending this in birds 13.  Compared to mammals, birds give  you much more scope for variation. Different bird species will go from being entirely solitary to being in groups of 50,000. He was able to look at some of the neural circuitry of steps in  group preference, steps in territorial size preference.  His work suggested all of  these preferences could be represented in similar ways: “I feel comfortable when I’m in about an acre of ground and I feel lonesome if it’s two, and I feel anxious if it’s half, and I’ll move and I will change things in order to get to the situation that I prefer.” Once you start to think that way, you can see how much leverage you can get when you’re using these basic motivational processes to imagine how you can construct a nervous system. I think – and I’ve argued in print with Supriya Syal…for  a theory of language based on motivational changes 14. I think it’s the motivational circuitry that’s changed in the context of a large cortex and some ability to speak. What’s different about humans is that we really care more than anything else to influence mommy or caretaker by talking or waving our hands.

DSW: Well, I can’t resist. I didn’t anticipate talking about this. Christopher Boehm’s work and the concept of major evolutionary transitions makes the unique human evolutionary event social control, so that rather than a typical dominance hierarchy, the would-be dominant individual is controlled by the subordinates. That created a sort of enforced egalitarianism that made more cooperation possible. Other primates, including chimps, cooperate to a degree, but members of a group are also their own chief rivals. Basically, teamwork became the signature human adaptation and symbolic thought – many forms of communication, including symbolic thought– are forms of teamwork. They’re low-cost team work but still, a symbol is shared, and there’s something very communal about that.  Michael Tomasello’s work–simple things like pointing and shared awareness, all follow upon this major transition. So does that fit into your scheme?

BF: Yes, completely, so you’ve got these interesting things–like we have this obvious morphological specialization of the whites of our eyes, so we can tell where we’re looking. We are very attuned to that–and talk about a subordinate dominating an adult–look at these babies that are getting their mommies to talk to them! So I think this is all part of the same general thing and it doesn’t require adding a cooperation circuit. It says “let me to use my learning machine to understand that thing.”

DSW: Great.

BF: I think that things are moving nicely in neuroscience with Karl Deisseroth and optogenetics–being able to dissect out complex motivational circuitry, which is massively intertwined wires and cells at the base of the brain that no one could know a thing about before. But now, for the first time, those are getting to be dissectible.

DSW: What’s the technique that enables that?

BF: Optogenetics. This guy’s managed to be able to turn off genes or whole cells or neurotransmitters, or make cells fire or not in the brain in response to a light pulse nearby them. So this is uniquely useful in places where there’s complex convergence circuitry. People have been spending so much time looking at the cortex because it’s sort of easy — the dimensions are all spread out and laying flat for you. But the base of the brain–that’s much harder. I think that’s where the action is going to be in this almost roiling motivational circuitry that is so easy to change. To extend the domain of the vasopressin receptor, or to produce it in some different tissue, or any number of these neuromodulators that can change the organization of cognition. That wasn’t part of the explanatory language. There was no way for it to be with classical Evolutionary Psychologists.

DSW: Yeah for sure. It was very much an outside-in kind of thing, not mechanistic. Phenotypic modularity, however it is implemented mechanistically. Well, let’s end up with your own EP hypothesis, “The Pain of Altruism”. Tell us what that is.

BF: So, this is about rewiring another motivational system. The idea is that humans haven’t changed the nature of pain in general but we’ve changed the set of things that are designated pain15. I watched a bunch of monkeys who had undergone (in lovely conditions) caesarian sections, where I was looking at retinal development very early on16.  I was sitting with the recovering mothers and in about an hour these gals would be up and about, banging on each other if you let them and wanting their lunch.  I wasn’t a bit like that when I had a caesarian section! So finally I said, “Wait a damn minute!” I was very influenced by a book by Wenda Trevathan called Human Birth: An Evolutionary Perspective,  and books by Sarah Hrdy. Human birth is always assisted and in other primates, birth is practically never assisted. So I started to think that there’s a whole class of things, including labor, recovery from trauma, and probably diseases from viruses, where because we can ask for help and get it, these things have been designated painful in an evolutionary sense that aren’t painful in other animals, because there’s no use for them to be in pain. For example, having painful labor for an antelope in Africa would leave that animal incapacitated for hours. Writhing on the ground, crying in pain trying to give birth to an antelope makes them become lunch, not  mothers!  That doesn’t happen. So if you look at large ungulates giving birth, with large hooves and all kinds of horrible stuff, they show rather little evidence of discomfort. That’s not to say that birth isn’t dangerous—it is! There’s high mortality associated with birth, but that’s not when humans are yelling. They’re yelling when their cervix is dilating, which isn’t dangerous at all. So that’s designating a stretch of particular smooth muscle to be something that’s putting me in extreme distress, making me call for help, to have a better chance of survival in anticipation of the event that happens later. The missing concept in most people’s minds is that pain is to cause action–it’s not just the automatic sensation  of damage. Other animals have pain when it’s for something, like get off my foot, stop biting me, or if I possibly can, I should lie down and recuperate. But most animals don’t have that luxury, unless they’re babies. I think we’ve taken a mother-infant behavior module (kind of!) and expanded it.

DSW: So does that imply that in other mammals, because the care-giving relationship is the mother-offspring relationship, that infants would feel pain?

BF: Yes, that is an unfortunate consequence. So yeah, I remember used to think when exasperated with my own bables, “You’re just crying because you want to irritate me!” But maybe they’re crying — I can’t prove or demonstrate this—because the experience of pain keeps the call for help honest. It is an honest signal.

DSW: There are also contextual factors and cross cultural factors. That would fit into the hypothesis.

BF: Essentially, though, I am arguing that there are a number of physiological states that don’t count as pain in other animals.

DSW: Basically what you’ve done–and this is why I called it an EP hypothesis–is that you presented an adaptation hypothesis that our species has certain selection pressures, which are not experienced by other species, to put it crudely. Then there’s the question of how it happens mechanistically. Would you talk about gating mechanisms?

BF: So this would be the same kind of thing where some new class of inputs gains access to the “yeow make it stop” circuitry. All this input does cohabit and it’s not a crazy amount of re-organization to imagine. But how it very specifically would happen I have no clue. I think it’s something that needs explanation and I do think it falls under this changed motivational envelope rather than the redesign of the whole circuit.

DSW: You do get accounts of men in battle not feeling pain.

BF: Yes, that’s an interesting thing. I learned that this is not human-specific at all. It is cross-mammalian.  The prototypical human battle story is   “I got my leg shot badly, but still I picked up my comrade and got him back to the hospital, and only then I noticed my injury..”. It turns out that in most mammals that have undergone some major trauma, the first thing they do is get the hell out of there.  Later they try to attend to their wounds.

DSW: And as they’re getting out of there they’re not feeling the pain. So humans are capable of being like other animals in certain respects.

BF: Yes. It’s not a human specific, battlefield specific evolved thing.

DSW: This has been a wonderful conversation—I’m so happy to add it to our comprehensive series on Evolutionary Psychology. Thank you, Barbara!

BF: Thank you!


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Published On: February 2, 2016

Barbara Finlay

Barbara Finlay

Barbara Finlay is the W.R Kenan Professor of Psychology at Cornell University, and co-editor of the journal Behavioral and Brain Sciences. Beginning from sensory physiology and developmental neurobiology, she evolved into a scientist studying the  interaction of development and evolution in the construction of the brain.

David Sloan Wilson

David Sloan Wilson

David Sloan Wilson is president of Prosocial World and SUNY Distinguished Professor Emeritus of Biology and Anthropology at Binghamton University. He applies evolutionary theory to all aspects of humanity in addition to the rest of life, through Prosocial World and in his own research and writing.  A complete archive of his work is available at www.David SloanWilson.world. His most recent books include his first novel, Atlas Hugged: The Autobiography of John Galt III, and a memoir, A Life Informed by Evolution.

One Comment

  • quidnunc says:

    Thank you. That was very interesting although I didn’t understand some of what was said 🙂

    As a general reader I wonder if EP is being a bit misrepresented. In various popular books this idea of modules was always set against this idea that “functions” could be physically distributed. Maybe I’m too young to remember how Tooby, Cosmides and popularizers like Dennet talked about modularity in the 90s; was it not the case that this idea of a module-for was relative to information processing? so a recent article like this fits with what they were getting at:


    I do think it’s valid to criticize EP for not being agnostic about how “functions” decomposes into actual structures in the brain (and how they might be more general than the conceptual boundaries of the hypothesis) but we should be clear that the original motivations was in contrast to theories about much more general purpose conceptions of how the mind works.

    I recently listened to Dan Dennett talk about the evolution of language that is I think consilient with some of what is discussed in this interview


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