Stephanie Zvan has kindly transcribed the evolutionary psychology panel she was a part of for the Skepchick site. Seeing as the full transcript is now available and I have done some further thinking and reading around the subject I would like to have another look at the misinformation I feel is being pedalled here. There are also some points to clarify regarding my earlier posts on the subject.
A note on colour coding. Grey text is me, orange text is from the panel and green text is quotes from other sources.
Stephanie Zvan: All right. We’re going to go ahead and get started. Hopefully, you’re here for the evolutionary psychology panel. If you’re not, you’re in the wrong room. I am not the expert on this panel on any of the things we’re talking about. My name is Stephanie Zvan, and I am here to mostly moderate. I’m going to ask everyone to introduce themselves. Indre, do you want to start?
I obviously have no particular problem with anything Stephanie says here, though I will point out that for someone who is there to "mostly moderate" she seems, by the end of the panel, to be more of a commentator than a moderator. In retrospect I do find it something of an indictment of the panel that it is assembled from five people who posses little knowledge of what evolutionary psychology is and who are generally dismissive of it. I'd like anyone who ends up reading this to think about that and ask themselves why no one who is sympathetic to the field and/or possesses any sort of qualification in evolutionary psychology is involved.
Indre Viskontas: Sure. My name is Indre Viskontas, and I’m on this panel in part, I think, because I have a PhD in cognitive neuroscience. So I represent the psychology side, but my background really is much more in hardcore neuroscience. So I did single-unit recordings from hypocampal cells in patients with epilepsy as they were trying to build new memories. Then I did some functional MRI work looking at those different subregions of those parts of our brains that are involved in forming new memories. And then finally, I worked with patients with dementia, who, in the course of their disease as they lose their ability to communicate verbally, sometimes develop a skill for and a passion for creating new art, particularly in the visual realm, as the part of their brain that no longer can use language seem to release some parts of the back of their brains, which is the visual cortex. So that’s my background.
PZ Myers: Okay, and I’m PZ Myers. I’m a biologist at the University of Minnesota Morris, and, like Indre, I actually have a PhD in neuroscience as well. That’s what I was trained in early on. However, all my work was done on much more interesting organisms: fish and grasshoppers. You know, things that are simple and stupid enough that you actually have a chance of understanding some little fragment of what they’re doing. But otherwise since I’ve become more of an evolutionary developmental biologist, I’m interested in evolutionary problems, and that’s how evolutionary psychology came to my attention. I’ll just say ahead of time: My bias is, I despise it.
SZ: Is that a bias or a conclusion?
PZM: It’s both.
Greg Laden: Okay. Well, my name is Greg Laden, and I am a biological anthropologist. And when I was in graduate school, just about the time I graduated, two researchers, a person in psychology and a person in anthropology, with whom I shared an advisor, gave a talk in room 14A of the Peabody Museum. One of them did all the talking. He put a big square up on the blackboard–a big rectangle. In the lower corner, he wrote, “DNA,” and in the upper corner, he put a little box and wrote, “Behavior.” And he said, “I would like to propose a project whereby we work out what’s going on in the middle from a scientific perspective.”
That was John Tooby and Leda Cosmides who gave that talk, and they are the parents of evolutionary psychology. They named it. They had been working on this for some time as their theses, and they were just coming out with their publications then. So I was there when it was born, and it wasn’t as ugly of a birth as you might have thought.
I think they’re right, that what I just said that they said is correct. It’s good, but evolutionary psychology developed and became a field unto its own – and we can talk about all this later, but it has certain premises and tenets. And my research was in hunter-gatherer studies, and human diet, and things like that, so I found right away some things that I didn’t like about what they were saying. So I spent the next seven or eight years going to their conferences and complaining to them about certain specific issues, and then I eventually got tired of it and stopped. And no one ever listened, and I didn’t have any impact at all. That’s why I’m still here.
Amanda Marcotte: I’m Amanda Marcotte, the only non-scientist of the non-moderator panelists. I’m a journalist. I write about a variety of things, mostly feminism, politics, stuff like that. I’m here, I think, mostly to translate why evolutionary psychology is so attractive in the media and particularly some of the more problematic of narratives that is sort of generates in the media.
SZ: All right. Eventually, we will open this up for questions, but because a lot of people have a lot of ideas of what evolutionary psychology is, we’re going to start by taking this back a little bit to the basics. And so, Greg, you were there at the start. Do you want to give us kind of where it went from those two little boxes.
GL: Sure. Actually, these days, when you use the term “evolutionary psychology”– I just did some Google searches and so on just a couple days ago in preparation for this, and it turns out the phrase means anything about evolutionary biology having to do with human behavior to a lot of people. But that’s not what it is. What is really is – and I checked a 2010 publication by David Buss, et al., which reviews everything.
I feel this is misleading. The overall exercise is best understood in the terms Greg has just claimed evolutionary psychologists go beyond. What is it about our psychology that can be best explained through an understanding of evolution? That's a good starting definition.
What Greg seems to be doing is taking some of the more rewarding lines of enquiry and suggesting that they are strictly definitive of the field. This is a little cheeky of him. Some of the things he brings up would certainly cause a great deal of rewriting were they to be somehow overturned, but other things he claims are definitive really aren't.
Also, whilst I do think reading David Buss is important in regards to understanding evolutionary psychology I do think he falls short of "reviewing everything". I rather like David's stuff (in fact Evolutionary Psychology: The New Science of the Mind is my favourite book on the subject) but I think his work is better understood in light of having read other books.
For example the further reading on Evolutionary Psychology that I was recommended by the Open University makes no mention of his work, instead it recommends:
How the Mind Works by Steven Pinker.
Human Evolutionary Psychology by Barrett, Dunbar and Lycett.
Evolution in the Mind by H Plotkin.
In the Shadow of Man and Through a Window by Jane Goodall.
Alas Poor Darwin by H and S Rose (a critique of the field).
As well as copious reference to various journal articles and The Selfish Gene.
So this isn't to say that David Buss isn't an important voice in the field (he undoubtedly is) but in my experience he wasn't amongst the primary sources recommended for students and I doubt I would have been able to appreciate his writing had it not been for primers such as the university course text and How the Mind Works.
And this is sort of illustrated by Greg himself - who clearly has a fairly shaky grasp of what it is that he is talking about.
GL: It still is the idea, not that our brains or our behaviors are somehow affected or shaped by our biology or evolution – and then beyond that you can do interesting things – but rather that our brains have domain-specific mechanisms that are relatively specified as to their neural connections – that are largely coded for by genetic programming but develop in the context of the environment they grow up in to do certain things well, which means that we’re probably also not good at doing certain other things.
Well, these things are not mutually exclusive. Our brains can have been shaped by evolution whilst also possessing or developing mental modules. In all likelihood some of them are more venerable than others, and some are more contingent on environmental input than others.
For example human babies tend to imitate facial expressions within minutes of birth. We can think of this psychological propensity to imitate as a mental module (or involving mental modules) and we can assume its innate as the behaviour is displayed shortly after birth and across cultures. The context of the environment has little to do with this, provided its a neurotypical baby with decent vision the behaviour can be expected.
On the other hand there are certainly innate propensities to developing language, but the manner in which they are exercised and developed will depend on an interplay between innate mechanisms and environmental input.
Greg also makes a rush to judgement when he claims that the mechanisms are relatively specified as to their neural connections. This isn't typically so as I will explain in the next bit...
GL: And that’s different than just having a brain that’s shaped by biology or evolution or that can learn things. Our brains are not a general learning mechanism in this field these days.
I think Greg seriously misleads here. It is not false to suggest that evolutionary psychologists propose (amongst other things) mental modules, which I suppose is what Greg refers to above.
Now calling mental modules "domain-specific mechanisms that are relatively specified as to their neural connections" is somewhat confusing. It's close enough to take as a genuine attempt to explain the phenomena, I suppose, but there are two problems with it.
1) It introduces a flawed understanding of mental modules which will go on to become a theme of the talk - that they are bits of the brain. The mental modules proposed by evolutionary psychologists are better understood as bits of behaviour. A portion of our psychology shown to be cross-cultural and therefore thought to be heritable. This may have implications for the brain but isn't "a bit of the brain" in the way that the panellists will go on to suggest, as Pinker describes here:
The word "module" brings to mind detachable, snap-in components, and that is misleading. Mental modules are not likely to be visible to the naked eye as circumscribed territories on the surface of the brain, like the flank steak and the rump roast on the supermarket cow display. A mental module presumably looks more like roadkill, sprawling messily over the bulges and crevasses of the brain. Or it may be broken into regions that are interconnected by fibres that make the regions act as a unit. The beauty of information processing is the flexibility of its demand for real estate. Just as a corporation's management can be scattered across sites linked by a telecommunications network, or a computer program can be fragmented into different parts of the disk or memory, the circuitry underlying a psychological module might be distributed across the brain in a spatially haphazard manner.
- Steven Pinker, How the Mind Works page 30.
2) Whilst Greg may have a (fairly obtuse) point in suggesting that "the brain is not a general learning mechanism in [the] field" he is wrong to suggest that this fact conflicts with a notion that the brain is shaped by biology or evolution. Clearly the brain can learn things, but not all human behaviour is learned and learning isn't the sole component of behaviours even when it does play a part.
GL: Our brains are shaped by evolution and programmed more or less genetically, again, with developmental factors, to be good at doing certain things that are the things that our ancestors living on a Serengeti-like ecosystem in Africa for two million years were faced with. That is what evolutionary psychology is pretty much defined as. And that’s how it was defined in the beginning, and those definitions haven’t really changed.
This is overwrought. That the time human beings spent in Africa is seen as particularly pertinent to certain behavioural propensities is true, but isn't definitive of the field. It is an interesting and rewarding line of enquiry in regards to certain issues. Obviously a great deal of our evolution occurred prior to the period Greg mentions, and the assumption that no pertinent evolutionary processes have occurred since is based on reasoning Greg makes no effort to either explain or challenge.
This introduces another theme of the talk, which is the casual dismissal of the notion held by many evolutionary psychologists that the African landscape of the Pleistocene was pertinent to the formation of our innate psychology in a way that no other place or time has been since, and that our innate faculties essentially reached their current form therein.
As Ed Clint says in the comments here:
Referring to these numbers without contextual information is meaningless. It is well known in biology that for some species millions of years go by with very little change. For others, speciation can happen in decades or centuries. The question is, what seems to be the case for us? What does the evidence suggest? When did important human-type faculties appear? Well, it probably wasn't 60 million years ago when the first primates emerged, as they were shrew-like creatures not much like humans or even apes. It wasn't 10,000 years ago either because we can compare modern populations whose ancestors were geographically isolated 10,000 years ago (say, New Guineans and native South Americans), it can't be the case that many isolated populations continued to evolve in exactly the same way.
So that leaves us with the time in between (and for some considerations, the Environment of Evolutionary Adaptedness (EEA) is much earlier; See Neil Shubin's Your Inner Fish).
The idea of the Pleistocene's importance to human evolution was just a hypothesis. It might have been wrong. It has turned out to be incredibly useful. It has helped us to make sense of ancient mysteries about human nature for the first time ever.
The sniff of indifference to a powerful idea which is, without question, expanding our understanding of what it means to be human is, frankly, grotesque.
GL: The Buss, et al. 2010 article actually goes through those specific points and says why they’re still right, despite some–and they have some good points – despite various criticisms. In other words, evolutionary psychologists are sticking to their story pretty much as it was when Cosmides and Tooby, and Tooby and Barkow, and so on came out originally.
SZ: So, Indre, that makes some particular claims about how our brains are organized. Are they?
This question is misleading. Once again the notion of mental modules make no direct claims about the organisation of the brain. Now you could take it that modularity of the brain is implied by the idea of innate behavioural tendencies, but they are not the same thing.
That this isn't specified or acknowledged makes the following commentary largely irrelevant.
IV: They’re certainly organized. And there are certainly a lot of different layers of organization in our brain. So, for any given person to understand how a particular function, for example, is represented in the brain, you really have to look at all these different layers. And I think that one of the ways in which evolutionary psychology sometimes glosses over some of the important details is by choosing a level, say, the level of a set of neurons firing in a circuit, and forgetting that every time that neuron fires, depending on which neuron is firing with which neuron, the way that it fires the second time is going to be changed, right, depending on how those neurons change with experience.
So you can look at the brain in so many of these different layers, and there certainly are some parts that are more modular than others, particularly when you look at the architecture of the brain. So if you look at neuroanatomy, you can see very beautiful, modular organization in different parts of the cortex. And different regions of the brain, of course, have very different architecture. And certainly these have evolved, right? There are some parts of our brain that are older, phylogenetically, than other parts of the brain–cortex versus some of the more–what we call the “reptilian” parts of the brain or the limbic system – parts of our brain that are involved in emotion.
But you then have to put it back into the context of the brain works as one thing, and certainly there are multiple systems involved, particularly what I study, which is memory, there are multiple, competing memory systems–sometimes they compete; sometimes they cooperate. But I think when you really try to nail down a particular function either in a particular region or at a particular level, eventually you’re going to have a problem because the brain doesn’t act in a vacuum. It’s highly interconnected, and that’s what makes it a brain. So that’s the caveat I would say when you’re trying to figure out modularity, although there certainly is, you know – it’s highly organized.
This is a fair response to the question, though please note that it isn't actually addressing anything about evolutionary psychology.
SZ: Amanda, you’re probably best suited to talk about the kinds of behavior that evolutionary psychologists are really saying are selected for.
Best suited other than, say, an evolutionary psychologist?
AM: Well, one of the things that is interesting to me, and is a big problem with evolutionary psychology, particularly the way it plays out in the media, is that humans have a whole host of social and other kinds of behavior. They focus on sex and gender to an extent that is a little bit obsessive. And often evolutionary psychology tends to sort of promote and perpetuate these rigid gender roles where women are undersexed, are submissive, are kind of vain and frivolous, and men are naturally violent, aggressive, oversexed, and status-seeking, I would say. And I don’t know that they generally have the evidence that they say they have, that these sorts of behaviors are ingrained and not taught to us, socialized. And I think that these kinds of behaviors, these kinds of stereotypes of men and women are something the media loves to cling to, because inherently, I think our media systems are kind of conservative. And we like to be told Just So stories about why we are the way we are, because it’s easier to do that than to listen to people who are demanding radical change.
I'd suggest that this is an overly cynical and hyperbolic reaction. I have never seen an evolutionary psychologist claim insight into female frivolity, for example. Nor have I seen any evolutionary psychologist promote the notion that women are submissive and men violent. They might well examine patterns in such attitudes according to gender, but so do other types of psychologist.
There seems to be a general notion that it is fine for a psychologist to examine such differences with an eye to society or culture, or individual differences, but not evolution.
Examining a phenomena is not the same thing as promoting it, and its easy enough to think of positive implications of recognising sex differences, as opposed to the alarmist implications that Amanda prefers to imagine:
People are mammals and we should think through the ethical implications of the fact that it is women who bear, nurse and disproportionally raise children. One ought not to assume that the default human being is a man and that children are an indulgence or an accident that strikes a deviant subset. Sex differences can be used to justify, rather than endanger, woman-friendly policies such as parental leave, subsidized childcare, flexible hours and stoppages of the tenure clock...
- Steven Pinker, The Blank Slate, page 358.
Our desires in a mate serve analogous adaptive purposes, but their functions do not centre simply on survival ... If we were to select a mate who failed to deliver the resources promised, who had affairs, who was lazy, who lacked hunting skills, or who heaped physical abuse on us, our survival would be tenuous, our reproduction at risk.
- David Buss, The Evolution of Desire, page 7.
SZ: PZ, they’re telling us that these behaviors have been selected for, that they’re adaptive. What kinds of criteria would they have to meet to show that behavior is selected for, and are they really doing that?
Well, they say that if you take Amanda's word for it - which you should not.
What you should do, I think, is ask an evolutionary psychologist what behaviours they think have been selected for and why they think that.
But anyway, let's agree they say certain behaviours are adaptive and have been selected for, even if Amanda hasn't made a good job of identifying them or reporting on them honestly.
PZM: No, they’re not really doing that. You know, Greg made that interesting point that when Tooby and Cosmides set up their program, they said, “Let’s find the connection between DNA and behavior. And I think that’s a perfectly reasonable goal, although really ambitious and complicated. So we looked at all the connections between DNA and behavior.
Unfortunately, what’s kind of happened is that the way evolutionary psychology is structured now, all they look at is the behavior, and then they infer the biological basis for it, the genetic basis for it, that they don’t actually do the work of going in– If you’re doing any kind of population genetics, if you’re doing evolutionary biology, I expect you to look at the genes, okay? Evolutionary psychologists don’t look at the genes. They assume the genes, and what that often means is that when you look at their assumptions, they’re naive and simplistic. So often what you see is an imaginary line, a dotted line going directly from a hypothetical gene to a behavior. And that’s not the way it’s going to work.
As Indre was saying, when we look at the actual brain itself, it’s all interconnected. It’s a spaghetti tangle firing. It’s all linked together, and it’s hard to say that this piece does one specific thing. You know, there is not a colring-in-the-lines module in the brain. There is not a module that says you like broccoli, right? It’s much more complicated.
And the same way with the genes. There isn’t a one-to-one mapping of genes to behaviors, but they assume it is. They always argue that it is. So that’s a fundamental error. If you’re going to talk about evolution and genes, you’ve got to start with the genes.
A couple of problems with this, I mentioned them in previous blog posts but I saw a very elegant answer to the first issue (that we need genes in order to examine a heritable trait) by Robert Kurzban on his blog:
Because evolutionary psychologists focus on hypotheses regarding function, the evidence is typically design evidence, following the logic laid out by George Williams. Indeed, many of us think that there was plenty of good evolutionary biology being done before anyone knew that genes existed. Charles Darwin, for instance, managed pretty well. Myers’ insistence on genes when studying behavior, however, doesn’t really set him up against evolutionary psychology so much as animal behavior and behavioral ecology more broadly. As I and others have pointed out, inferring function from form – morphology or behavior – is business as usual in animal behavior. Insisting on genetic evidence, then, isn’t a complaint specific to evolutionary psychology. (This difference in views might help to explain the expanding Coyne/Myers debate.) Denying that one can infer a trait’s function from its form puts one out of step with the mainstream biological community, as I’ve discussed before, using Futuyama’s textbook as evidence.
The second point is the claim about one-to-one mapping of genes, which was answered by Steven Pinker here:
Completely untrue – this was Gould’s claim in the 1970s, which confused a “gene for x” (indispensable in any evolutionary thinking, given segregation) in the sense of “increases the probability of X, averaging over environments and other genes” with “a gene for X” in the sense of “necessary and sufficient for X.” Every honest biologist invokes “gene for X” in the former sense; evolution would be impossible if there were no additive effects of genes. No one believes the latter – it’s pure straw.
I realise PZ has since responded to this, a reaction to his response is given in my previous blog post.
SZ: So, Greg, do you think they needed to start with the genes? I’ll ask the anthropologist.
I suppose an anthropologist is a good authority in lieu of, say, a psychologist or something.
GL: Well, I think PZ’s right. I don’t think they actually, though, infer it. I think they just assume, even, the connection.
I'm a bit bewildered in regard to this. What other method of inheriting a trait is there beyond genetics? Epigenetics?
Yeah, they infer it - just like anyone else would as a sensible first step, surely?
GL: Okay, there are two points I want to make, and I think I’ll just try to make one of them right now. I think that there are – I know from my own reading and research that there are systems of behavior– complicated systems of behavior in which a set of outcomes over here [gestures with right hand] are obtained and a set of outcomes over here [gestures with left hand] are obtained, but the things that cause those outcomes are distinctly different.
One of the most dramatic examples I can think of is eating an antelope, killing and eating an antelope or a deer. In one system, wolves eat deer. In another system, humans domesticate dogs, and dogs do things to deer when you’re hunting. Only they’re not deer anymore. They’re now sheep, and the sheep are acting like prey animals, and therefore they can be herded by your domesticated wolves. In both cases, you sit down and you eat a steak, but in one case you’re using completely different sets animals are being [used].
Now I think it’s probably true that there are behavioral things within organisms that work that way too. The actual genetic, hormonal, developmental, and neurological parts that end up with a certain behavior may be very distinctly different in different individuals. And one good example of that, which is actually evidenced, is reading and writing and how humans deal with other linguistic things that are in a more technological domain. And it’s harder to prove these things are going to be related to male indiscriminate behavior and female choosiness or something like that, which is the classic idea. I think that that would be interesting to study, much more interesting than having a normative system of behaviors that you then assume have basic modules underneath.
It's a bit frustrating to read this. There are whole books written about our innate propensities to learn language. The Language Instinct by Steven Pinker is an obvious one. To pretend, as Greg seems to do here, that this sort of thing isn't an important line of enquiry for the field and that "male indiscriminate behaviour and female choosiness" are somehow "the classic idea" is just misleading. Language and linguistics are huge topics in evolutionary psychology.
GL: I guess I will make my second point really quick. For several years, every year, I did a study for John Tooby. I did a favor for him in which I did an experiment with several students. The experiment involved giving them a series of two tests. In one test, they were given a certain logical problem they had to solve. In the other test, they were given the same exact logical problem they had to solve. But in one test, it was a problem involving how to figure out how a temp had fucked up your files. You’re a file clerk, and you have to figure out how the temp that came in messed it up. In the other one, you’re a bartender, and you have to figure out who at the table is lying to you about their age. The students pretty much got 85-90% correct answers as the bartender, but they couldn’t handle the file clerk thing.
Tooby claims that this is because we evolved more like as bartenders on the Pleistocene savannah of Africa, which – [laughter] No, this is valid. It’s knowing who’s lying to you as a hunter-gatherer. You’ve got to know your social relationships, fine, so file clerking doesn’t matter. What I would argue is that we’ve actually grown up in our own world in which who lies to you matters – your friends, your parents, your siblings – and not as file clerks. If we lived in a society in which file-clerking was actually something you did as a child, as play, and you grew up doing this, if this was behavior you normally encountered – We know this, for example, that men and women test very differently on things that have to do with spatial relationships of objects until both males and females start growing up playing the same video games. And then they test the same way.
I mentioned this in a previous blog post. Just to recap quickly, what Greg does not mention is that these tests are just part of a series of experiments designed to examine the same phenomena. The reason Tooby puts such things down to more than just socio-cultural factors is that less obvious types of comparison lead to the same results, and these same patterns of results are shown cross-culturally.
GL: So I think, yes, there are modules in our brains that are there that can be good at certain things, but I simply would argue that, for the most part, 90% of those modules emerge because of our experiential background, and 10% of genetic imperative or something, whereas the evolutionary psychologists would argue the opposite.
This is one of the most common misconceptions spread about evolutionary psychology - that evolutionary psychologists see nature and nurture as mutually exclusive. In fact, rather than them arguing the opposite they would more likely suggest that many modules may be more or less influenced by experiences, culture and/or innate factors.
In fact, for cultural shifts to have kind of predictable consequence they must be acting on innate propensities as far as I understand things. Typically Inuit people wear more clothes than !Kung bushmen - a sociocultural phenomenon explained through a natural propensity to enjoy a comfortable temperature.
AM: I want to pop in and point out one other thing that jumps out to me about that example. He did this on college students?
AM: Well, college students are obsessed with trying to get into bars without [laughter] This is a problem they think a lot about. I mean maybe that goes to the problem a lot of people don’t understand, like the reader in an audience reading the article a journalist has written about a paper that’s been published. They often have no idea who these studies were even done on.
GL: These weren’t even the students that show up to get the $5. These were the students in my class, and it was an option. Sit the rest of lecture or you can sit there and take this test. And most are going to take the test.
This is flat-out wrong. The experiment has been repeated in field studies involving diverse participants. A paper explaining the performance of the Shiwiar tribe in such tests can be found here.
IV: I just want to jump in. Greg’s really come up to something that’s very critical to our understanding of the brain, which is that the brain is very plastic. We used to think that you were born with a certain brain, and that once it finished developing, no new neurons were born. That was it. You just went through this slow decline. We know now that’s not true. In fact, there are certain parts of your brain, particularly in the memory regions, that actually grow new neurons even later in life.
Even at the simplest level, the level of what a neuron, a single neuron is interested in, right? So a neuron communicates with other by either firing or not. It either sends an electrical signal downstream, or it doesn’t. It’s binary. But what it fires to, what causes it to send that signal can change depending on your conscious environment. I actually watched this happen in some of my patients where we were recording from their hypocampal neurons. When I told them, “I need you to remember, now, this particular face,” a cell all of a sudden would perk up and start firing in a way that was indicating that it was marking whether this particular face was novel or familiar.
But when I had that same person do a different kind of task, like, for example, drive a taxi through a virtual town and pick up passengers, that same cell would have a different thing that would set off its firing. So, for example, it might become a place cell. It would only fire when the taxi was in a particular location in space. And so we see the receptive field of these cells change depending on what the person is doing, even at the level of single cells.
I mean, when you think about it, that’s amazing, especially if you’re trying to say that the brain is modular and this region does that. Well, it totally depends! It depends on what you’re thinking about, what your goals are, how you’ve been raised, what you’ve done, because the brain is plastic.
Plasticity is another theme of the panel and it is also misleading. As Steven Pinker says here:
Plasticity is just learning at the neural level, and learning is not an alternative to innate motives and learning mechanisms. Plasticity became an all-purpose fudge factor in the 1990s (just like “epigenetics” is today). But the idea that the brain is a piece of plastic molded by the environment is bad neuroscience. I reviewed neural plasticity in the chapter “The Slate’s Last Stand” in The Blank Slate, with the help of many colleagues in neuroscience, and noted that the plasticity that allows feedback during development and learning during ontogeny is superimposed on an innate matrix of neural organization.
This did generate a response from PZ Myers which I discussed in the blog post prior to this one.
The idea here seems to be a return to the notion Greg forwarded earlier that evolutionary psychology somehow stands at odds with the idea that the brain can learn things. Of course this is nonsense. What it would say is that the brain's ability to learn has arrived via evolutionary processes, and that innate behavioural tendencies also exist.
PZM: Greg also brought up an interesting contradiction within the field of evolutionary psychology. One peculiarity, and I really think it’s a peculiarity because it’s not a necessary conclusion at all but you find it in the literature is that they argue that all the relevant evolutionary changes happened 10,000 years ago or more. They basically say you have to explain everything in terms of Paleolithic hunter-gatherers as if anything that’s happened since is negligible in its consequences on our biology.
As Greg mentioned, reading, writing, things that we – this group in particular, we do this all the time, right? This is what we’re focused on in our lives. And this apparently is not of any significance at all in evolutionary psychology, which you know can’t be true. The fact that these primitive hunter-gatherer brains – again, that’s there inference, not mine, that it’s primitive – can adapt and read science fiction novels is kind of amazing, right? It’s got to be plastic. I don’t think it’s genetic. It’s a capability of the brain to adapt in particular ways.
This is nonsensical. People from cultures that never had a history of reading and writing can nevertheless be taught how to read and write. Therefore the innate components of human brain allow for reading and writing and may well have done for 10,000 years or more.
Also the jab about evolutionary psychologists inferring that the hunter-gatherer brain is primitive is counter to the facts. In one moment PZ finds it bewildering that evolutionary psychologists say we are equivalent to ancient humans, the next moment he suggests that evolutionary psychologists unfairly deem ancient humans to be primitive. This is having his cake and eating it.
Many theorists wonder what illiterate foragers would do with their capacity for abstract intelligence. The foragers would have better grounds for asking the question about modern couch potatoes. Life for foragers (including our ancestors) is a camping trip that never ends, but without the space blankets, Swiss-Army knives and freeze-dried pasta al pesto. Living by their wits, human groups develop sophisticated technologies and bodies of folk science.
- Stephen Pinker, How the Mind Works page 188.
SZ: [points to audience member] Sure.
Audience question 1: There’s a study in Russia on silver foxes that started 50 years ago about breeding domestically, and they’ve started to go about breeding wild stock. They’re showing there are differences in the genetics. How would that come into this?
SZ: I’ll just repeat the question. He’s asking about the silver fox study in Russia, in which they several years ago started breeding essentially tame foxes. They saw, when they were selecting for behavior, quite a few changes in physiology and that sort of thing. And he was asking how this would be connected.
PZM: I would actually say that there are a couple of important points in that study. One is that these are capabilities that are present in the silver fox population. It’s so quick that it didn’t require mutations. What it required was novel recombination of traits already present in the population. And I think that’s another thing that evolutionary psychologists downplay, is the genetic diversity that’s present. So what you do, is you shuffle those, and you get combinations and – by the way, they also selected for more feral foxes, foxes that were more aggressive and violent, and that worked too. It was very easy to do.
The other important point of that study the significance of pleiotropy, which I think ties into everything we’ve been saying here, is that all these things are interlinked in complicated ways. When you select for domesticity, what you end up doing as well is you end up selecting for traits like different pigmentation. The more domestic foxes had droopier ears, for instance, like a dog. They tended to have spotted coats rather than uniform coats. Lots of things like that happened. So everything is tied together genetically. You change one thing, and it may ripple through and cause all kinds of other consequences.
PZ is making it sound as if evolutionary psychologists are ignorant of things like gene interconnectivity and that they rely overmuch on assuming that natural selection is the only driver of evolution. Now this is a charge he has made before and it has been answered by evolutionary psychologists. A good reply is provided by Jesse Marczyk on his blog and PZ hasn't offered any sort of response to this. This sort of objection was anticipated by the advocates of evolutionary psychology more than a decade ago:
One claim is that reverse-engineering, the attempt to discover the functions of organs (which I am arguing should be done to the human mind), is a symptom of a disease known as "adaptationalism". Apparently if you believe that any aspect of an organism has a function, you absolutely must believe that every aspect of an organism has a function, that monkeys are brown to hide amongst the coconuts. The geneticist Richard Lewontin, for example, has defined adaptationalism as "that approach to evolutionary studies which assumes without proof that all aspects of the morphology, physiology and behaviour of organisms are adaptive optimal solutions to problems." Needless to say there is no such madman.
- Steven Pinker, How the Mind Works page 165.
GL: I’ll expand a little bit on the EEA concept that was brought up, sort of define that. The idea is that, as PZ said, they want everything to relate to things that evolved, that happened 10,000 years ago or more. The concept is that the environment of evolutionary adaptiveness, which is difficult, because the word “adaptiveness” doesn’t exist, except in this term. But the EEA, when I first heard that word and then I went to these conferences, I wanted to find out more. That was my main criticism, was of the EEA concept.
Note that the A in EEA stands for "adaptedness", not "adaptiveness".
GL: I remember going to my adviser, Irv DeVore, and saying, “Where did this word come from? Have you heard it before?”
He said, “Yeah. I think I read it in Bowlby. Check Bowlby.”
So I went and looked at his shelf, and I found, actually, the bible. And it was an interesting bible. It was given to Irv when he was a child preacher, and I went back and said, “You were a child preacher?” But that’s another story.
Bowlby, I finally found it, and Bowlby has a chapter called “The Environment of Evolutionary Adaptiveness” in this psychology book. And it’s got a footnote. “The term environment of evolutionary adaptiveness–”, this is the first sentence, “–refers to the period of time over which a trait has undergone selection.” Footnote: “This idea comes from a conference I attended at which the idea was by Irv DeVore,” who is the guy who told me he thought he heard it from Bowlby.
But anyway, in the original Adapted Mind, the book that put out the first papers on evolutionary psychology, there is actually an article explicitly stating the EEA concept as being the savannah of the Serengeti. It says this is the environment in which people like the bushmen would have been living for two million years. And the paper explored our interest in bonsai trees and certain other landscaping things.
As Robert Kurzban points out:
From the last sentence, it’s clear he’s referring to the chapter by Orians and Heerwagen, “Evolved Responses to Landscapes.” While it’s true that they wrote: “The savannahs of tropical Africa, the presumed site of human origins…” but, and I can’t stress this enough, the “presumed site of human origins” is not the same as the EEA concept. Like modularity, the EEA concept is a technical term, and has been laid out in such exquisite detail – including in the Psychological Foundations of Culture chapter in the book Laden refers to — it really is striking that critics of the field still manage to get this wrong. Indeed, the abbreviation EEA doesn’t appear in the Orians and Heerwagen chapter (according to my Amazon and Google searches inside the book). (I tried to help Laden out on this issue back in December of last year.)
GL: So you had the individual lone tree on the landscape with the vast grassland, and that’s an aesthetically preferred or nice thing to us, which is maybe true. And that is because we evolved in that environment. That tree would be important. It would be where you would run when you were being chased by something.
What’s absurd about that is the Serengeti is full of archaeological sites that represent human prehistory. But all of those archaeological sites – Olduvai Gorge is on the Serengeti–all of those archaeological sites are known to be wooded and forested areas and very different from the living Serengeti. If you go to the Serengeti now, the place where The Lion King was, quote, filmed, like that place. Pride Rock is really there; it doesn’t look exactly the same. They actually went and drew pictures and made that.
Anyway, if you go to there, what you’ll find there is there is not a single primate living in that open Serengeti habitat, because you can’t be a primate living in that habitat. Water is too far away, and the only water you can get to is surrounded by lions, and there’s too many predators. There are lots of primates in the region, but they’re not on the Serengeti that the bushmen supposedly lived on. And the bushmen don’t live in the Serengeti either. They live thousands of miles away in the Kalahari. The nearest hunter-gatherers are the Hadza, who live sort of in the woodlands.
The point is this was people, I’m convinced who knew about human evolution stuff. They went and visited Olduvai Gorge. They went and visited places in South Africa. They did their tourism stint on the Serengeti and were in awe and wonderment about the Serengeti as a place in which we evolved. And they were visiting from inside of Land Rovers as tourists and just made that mistake, made that connection very erroneously. And that’s why we’re stuck with that very cartoon version of the environment of evolutionary adaptiveness for humans.
All interesting stuff, but of little relevance to the topic of the EEA as proposed by evolutionary psychologists. To quote from the Evolutionary Psychology FAQ:
The Environment of Evolutionary Adaptedness. This phrase, first coined by John Bowlby of attachment theory fame, has been the source of much confusion and controversy. First of all, the EEA is NOT a specific time or place. Roughly, it is the environment to which a species is adapted. Animals that lived in different environments or made their livings in different ways faced different reproductive problems, and that's why all animals aren't the same. Fish faced different problems than did butterflies, and as a result they have different adaptations. The EEA for any specific organism is the set of reproductive problems faced by members of that species over evolutionary time. The EEA for a particular species of fish is likely to be completely different than the EEA for a particular species of butterfly, even if those species both evolved in the same locations over the same periods of time. Each of these species faced reproductive problems that the other didn't, and thus their EEA's are different. The EEA concept is very similar to the notion of 'niche' in evolutionary biology.
So ultimately the fact that the Serengeti is currently uninhabited is of no consequence.
PZM: Yeah. Another thing about this too is I think a lot of the things that evolutionary psychologists are make assumptions to simplify their lives and to give cartoonish versions of what they’re explaining. And one of the things you find is this idea of the Paleolithic hunter on the grassland, but as you know well, that’s not a situation in which you get one uniform type of culture emerging. Africa is extremely diverse, and they’re ignoring the fact that this one environment can generate thousands of different kinds of lives out of it. So how can you then take a particular pattern of behavior and infer back to an environmental climate.
Modern people are culturally diverse.
Evolutionary psychologists reckon modern people are psychologically equivalent to those living in the late Pleistocene.
So it stands to reason that those of the late Pleistocene would be capable of cultural diversity.
So what is PZ on about?
GL: And their counterargument is, “Ah, but you’re still being chased by predators. You still have to mate.” And they will have a list of things that are still true for everyone. And they are still true for everyone, but they’re also true for all mice and all houseflies and everything else. So at this point, we now have the EEA apply to life in general, and therefore, all organisms should have choosy females and promiscuous males.
Relative to the investments they make during reproduction, yes, you tend to see such a pattern.
Among all four thousand species of mammals, including the more than two hundred species of primates, however, females bear the burden of internal fertilization, gestation and lactation.
- David Buss, The Evolution of Desire, page 20.
PZM: I read one paper by an evolutionary psychologist that was trying to pin down this idea of the modules in the brain. Okay, they were going to show us that there actually are these modules in the brain. And the one they found was the amygdala.
Okay, now maybe you don’t know, but the amygdala is everywhere. Fish have an amygdala. So how can you justify saying that this is a site for a specific adaptation for human beings when it’s something so universal. As Indre was mentioning, the brain is very well organized. It’s got a structure to it, but a lot of this structure is ancient, and its not going to be defined by events 10,000 years ago on the African savannah.
This ridiculous really. Without knowing what PZ is talking about and the surrounding context it is impossible to know who this unnamed evolutionary psychologist is or what he or she claimed. PZ may well be flat-out mistaken as Robert Kurzban explains here:
From this, it’s clear that Myers doesn’t understand the way the term “modularity” is used in evolutionary psychology. The fact that he thinks that the fact that “the amygdala is everywhere” is relevant to this discussion is startling. (I should say for the record I have no idea what “paper by an evolutionary psychologist” he’s talking about. If anyone knows, I will be pleased to add a note here and link to it. For the record, I’m guessing that the paper in question was not, in fact, written by someone who self-identifies as an evolutionary psychologist and that the paper did not, in fact, appear in one of the field’s journals.) The point is that by referring to “a site for a specific adaptation” he reveals, again, that whatever it is that he despises, it’s not evolutionary psychology.
To try and clarify in my own words, the amygdala may well play a part in a number of mental modules, and some mental modules may well be confined wholly to the amygdala. That the amygdala exists in other organisms doesn't challenge evolutionary psychology, in fact it stands to reason seeing as some of the mental modules proposed by evolutionary psychologists presumably arose long before humans did.
IV: Well, that’s interesting that they said the amygdala, which is made up of a series of nuclei that’s not nearly the – what I thought you guys were going to comment on, and I want to just jump in and play devil’s advocate for a moment, is that the reason they pick this timeline is because there is some evidence that the ratio of the neocortex – which is our sort of the newest part of our brain, the part of our brain that seems to be the most different from other species – to the rest of our brain increased exponentially around that time. I mean there is a certain time in which we see these graphs of whether it’s skull size or – We can sort of trace back this big leap in terms of our brain size, brain ratio to body size, and it makes this big leap.
So people point to that part as “Something happened there that we needed to adapt this bigger brain.” And so we dealt with this whole birth canal issue and now we have the fourth trimester of the woman. You know, the babies are born totally useless because their brains would be too big if they were born when they should be born, which is at twelve months rather than nine months.
Anyway, that’s why people sort of point to that time period, and you’ve brought –
It isn't the sole reason why. Other reasons include the fact that this period is the earliest period in which we find artefacts that speak to humans beginning to make art or play music or practise ritual. Another reason is that this is the period in which racial diaspora began to occur (the reason being that if the present day races are psychologically equivalent then our common ancestors must have been so too).
Genetic comparisons of mitochondrial DNA across extant human populations indicate that ancestors of this relatively isolated population of Khoisan people, along with those of some other remnant foragers in Central Africa, split off from humankind's founding population at a very early date. Both men and women carry the mitochondrial DNA characteristic of the deepest roots of the African Phylogenetic tree from which all modern humans descend.
As among our earliest Pleistocene ancestors, Ju/'hoansi women gathered and the men hunted, with communities sharing the fruits of their labours.
- Sarah Blaffer Hrdy, Mothers and Others, page 12.
PZM: But the time period they point to is not a point, right? It’s two million years.
IV: Right. Well, I don’t know if it’s two million. Certainly tens of thousands.
PZM: Oh, I think it’s millions. No, I –
GL: It’s [garbled] two million years. In Tooby’s writing, it’s explicitly two million years. And it’s two million years of the Pleistocene, which is the most dynamic period and Homo erectus as a species. Homo erectus is the first species to be found in increasingly diverse environments and altitudes and habitats. So you’re right, it’s ridiculous to point to that.
It's "ridiculous" to point to a period of time because of it's apparent length?
I would have though it all the more sensible.
Are we still evolving? Biologically, probably not much. Evolution has no momentum, so we will not turn into the creepy bloat-heads of science fiction. The modern human condition is not conducive to real evolution either. We infest the whole habitable and not-so-habitable earth, migrate at will and zigzag from lifestyle to lifestyle. This makes us a nebulous, moving target for natural selection. If the species is evolving at all it is happening too slowly and unpredictably for us to know the direction.
- Steven Pinker, How the Mind Works page 205.
AM: I want to point out that I don’t think anybody on this panel, or any of the critics or skeptics of evolutionary psychology would deny things like human women carry and breastfeed their children and that’s just part of our species behavior. I don’t think we’d deny anything like that. It’s just what they start to extrapolate from that is what I think we’re calling into question.
Is this a tacit admission of what we surely all know by now, that the panel is deliberately constructed from those critical of the field?
IV: Yeah, and so I guess the point I was trying to get to eventually – sorry that was so long-winded– was that the part of our brain, then, that seems so different is certainly not the amygdala. It’s the frontal cortex and the neocortex and all these other regions. So if we’re going to look at anything, we should look there. And of course, that’s the most complicated part too.
Well, no. Why would it only be the recently evolved parts and faculties of the brain that are of interest to evolutionary psychologists?
The "old" bits still do stuff in our minds, do they not?
PZM: Yeah, but that’s what I was finding, was that when you actually find evolutionary psychologists who are willing to talk about the real data and get down to the basics, they can’t point to anything that’s unique to humans in the last 10,000 years.
Isn't he contradicting himself here? Evolutionary psychologists don't think anything unique about the mind developed within the last 10,000 years. PZ said so (as a complaint) earlier. Now he is saying the opposite (also as a complaint).
So he's having his cake and eating it. Earlier he was scoffing at them for saying there was no change and now he's saying they can't point to anything unique in the last 10,000 years - the fact of which is an upshot of there being no apparent change.
PZM: They have to go to things like the amygdala or breastfeeding. You know, that’s a mammalian characteristic. We’ve got 80 million years of that to discuss. It means that the stuff they’re talking about, the very specific stuff that they’re testing on college students, they don’t have genetic or biological evidence for any kind of difference.
What about theory of mind? This is the ability of an individual to guess what another individual may be thinking. It's a fairly big topic in the field and appeared relatively recently in evolutionary time. It does not seem to present in the vast majority of mammals. Whilst some apes show some grasp of the skill the ability of humans at theory of mind tasks seems uniquely prodigious, and there is some degree of genetic evidence to back it up as well as a number of experiments performed on other species:
Consider one recent experiment. A psychologist placed food in various places, some items in view of a dominant chimpanzee, others out of his sight, whilst a subordinate in an adjacent cage was allowed to watch. When both were released into the cage with the food, the subordinate took advantage of his advance knowledge to bypass the food in plain sight and make a beeline for the hidden treats.
- Sarah Blaffer Hrdy, Mothers and Others, page 34.
SZ: I would like to emphasize at this point that we’re talking about good evolutionary psychology. We haven’t even gotten to evolutionary psychology as practiced by economists, so….
[points] You had a question.
Audience question 2: I did. It’s more for Indre. Is the current position of where the evolutional brain is now as opposed to men and women. You can see that women are much better multitaskers, far better memory than men, stuff like that.
IV: No, you can’t. Absolutely not. There’s so much BS about female and male differences in the brain that it’s unbelievable.
Audience question 2: Well, we do our awards at college and stuff like that, and for the Phi Beta Kappa and stuff like that and consistency – the school has got the same amount of men and women, but five times more women than men are coming to the top of the scale of education. I’m just wondering whether you see that, that there’s some type of a difference between men and women, because clearly, what we’re seeing –
AM: Nobody denies that men and women are generally different. I mean, if they weren’t in our culture, you wouldn’t even be able to spot who was male and who was female on sight. But that’s not because of biology. A lot of that’s culture. I mean, why do women make different choices than men? Well, a lot of the time because that’s what is coded as female in our culture.
And that is always adapting, so something like, you know, being bookish and spending a lot of time studying is something that, in the nineteenth century, was considered very masculine, and actually that women were not smart enough for that. Now our culture thinks women are kind of the smarter, more bookish sex because that’s something we associate with being kind of indoorsy, a little more personality submissive, whereas we encourage boys to run around and play. And masculinity in our culture is coded as being a little more anti-intellectual. So it’s not a big surprise to me to see women excelling in college beyond men. It also isn’t surprising to me to see that not reflected in economics, because once you get into the job market, behaviors we code as masculine, like being aggressive and competitive start to become more relevant.
IV: And then, in terms of the bottom line of neuroscience, there’s one major difference between men’s brains and women’s brains that I can say unequivocally is true: Men’s brains are bigger. Men have bigger skulls. Men are taller. Men weigh more. So that’s a big physical difference.
Now, that’s not to say that if you look at the tails of a distribution and so forth– So obviously, if you’re going to compare a big population of men and a big population of women, you might find some differences at least in terms of brain weight.
Now, again, how we use that brain is what’s really important. In terms of the functional imaging studies between men and women, there’s far greater individual variability between individuals than there seems to be between genders. One of the reasons why we sometimes see fMRI studies that are all male or all female is simply because when you’re comparing different brains, size matters. When you have to put them into an algorithm that’s going to compare different functional characteristics, you need to make sure they’re all pretty much the same size. So because men have bigger heads, we might use them for one study. Because women have smaller heads or whatever, we might use them for another. And that’s where we are.
But in terms of, I would say, a consensus in neuroscience between men’s brains and women’s brains, the counter-studies far outweigh, at this point, the studies that show there is a significant and replicable difference.
PZM: Years ago, I was actually a participant in some research where we were analyzing brains for sex and gender differences, where you get these thin sections of defined regions of the brain. We were looking in the magnocellular area from a portion of the cortex, and what we were doing was collecting statistics on, “Are there significant differences between men and women, between men and gay men, between men and lesbians, etc., doing all that.
The end result of the study was that, yeah, you could sort of see a statistical difference between men and women, but as somebody who was sitting there doing the data collection, oh, it was a mess. There were cell sizes all over the place. We saw clear evidence, for instance, that if a person was malnourished at death, they had smaller cells in this area. So there are these environmental effects that disturb it, which means that even when you do see an anatomical difference in fine details of the brain, it may be a consequence of culture as well, and you just can’t sort it out.
Audience question 2: It’s possible it’s a society thing, and it’s a matter of it being–
IV: It’s almost certainly a society thing. I’ll just go out on a limb and say that.
My apologies for the wall of orange text with no comment. I don't want to miss bits out in case it looks like I'm editing the panel in order to make a better case.
I will however take this opportunity to once again state that Evolutionary Psychology is not primarily interested in differences between the physical brains of people - it is focussed on differences in behaviour. If male and female brains were highly different, but their behaviour the same - well that would be odd but it would be of secondary interest to evolutionary psychologists.
Whereas if male and female brains were apparently the same, sex differences in behaviour would still be of interest to evolutionary psychologists (even if it became something of a puzzle as to how they occurred).
As it is the fact that typical male and female brains do seem to differ a little leaves a great deal of room for different behavioural propensities, because small alterations in the matter of the brain and the sort of chemicals found therein can have profound behavioural consequences.
So a genuine sex difference of interest to Evolutionary Psychologists (rather than the examples shared between the panel and audience here - which are more epiphenomenal) might be the way in which men and women differ in terms of how they think about space. That cross-culturally men seem to be better at thinking about how space works in terms of navigation, and women think better about how space works in terms of thinking about position within space.
That is a genuine phenomenon that is shown as a cross-cultural propensity.
It may have implications for girls doing better at school than boys if, for example, the school experience caters to girls in regards to this and other phenomena. But that is a more subtle implication of sex differences than anything the panel are discussing.
SZ: It is probably an economic thing, because at this point, men are still somewhat–not nearly as much as it was, say, 30 years ago – still somewhat able to make a living wage without higher education. Women are not. They mostly haven’t been, so that has pushed a lot of women into education. They have financial incentives to excel.
I doubt this. I think a more likely reason is that primary school teachers in the west are overwhelmingly female, and that this fact combined with peer pressure results in a culture in which boys lack an identity with educators relative to girls.
However, this is beside the point in terms of evolutionary psychology and the issue of boys and girls performance in education is certainly one of an interplay of numerous phenomena.
PZM: Stress and things like alcohol affect your brain. So if we did your brain studies before this weekend and after, we could see effects.
OK, why? Might that speak to our natural history at all?
GL: Most of what we do in science actually comes down to [to Marcotte] the opposite of what you do in journalism. I mean as journalists. We try to play around with variations. Systems that don’t have variations are not interesting. Whereas, instead of describing the bottom line, the central theme, let’s just look at the range of sex differences in humans. There’s a huge number of studies that have been done that show all different sorts of sex differences. How do we explain the variation that we see?
One of the variations you see is change in apparent sex differences over time. So if studies are showing differences over time going away or emerging, then this cannot be genetic differences that are explaining those variations. There could be developmental ones.
Also, the brain is an organ. You would not explain someone’s triceps on the basis of their ancestors’ triceps as far as basic size, as much as how much they go to the gym and do certain exercises. The brain responds to its environment, so that’s a source of variation.
Our brain - like our triceps - develops according to both innate propensities and environmental inputs.
So what’s interesting is that different people with different perspectives– It’s like if I wanted to explain to you why you feel better or not, today versus last week, and I’m a homeopathic practitioner, I’m going to do everything I can do to convince you that it’s the homeopathic remedy I gave you that explains the variation in how you feel. And if I think that genes are really important in determining behavior, I’m going to do whatever I can do to convince you that genes are explaining the variation in everything you have.
Having said that, I think that there are remaining interesting differences between individuals that may map out onto males and females more than just randomly on different people in the brain that have to do with some things. I don’t know if they’re going away or not. Having to do with, for example, linguistic-related issues. You seem to have deficits in language learning still much more often in young boys than in young girls, and you still have a larger number of simultaneous translators being hired, for example, out of females than of male populations. So I think there may be interesting things going on there. But still, again, if you went back 20 years, you’d have really solid evidence in experiment after experiment of some certain sex differences that have gone away with differences in child-rearing.
I don't think it's as simple as that, but certainly the one sex difference Greg cedes here - that women typically display a cleverness with language to a greater degree than men - is well understood by evolutionary psychologists.
Women's cognitive strengths and weaknesses vary with the phase of their menstrual cycle. When estrogen levels are high women get even better at tasks they typically do better than men, such as verbal fluency. When the levels are low, women typically get better at tasks on which men typically do better, such as mental rotation.
- Steven Pinker, The Blank Slate, page 348.
IV: And certainly sex hormones affect the brain, both during development and later on.
Ah, like I just credited Pinker with saying. OK, why? Might that speak to our natural history at all?
GL: Testosterone poisons male brains.
IV: Yeah. This is why estrogen therapies, for example, have caused women to have terrible memory problems. This has been documented as well. So anyway, there are hormonal effects that can be related to gender.
Right, and are you going to say how this relates to evolutionary psychology?
SZ: Yes. You had a question.
Audience question 3: Do you think the reason we play up the sex so much is because we’re predispositioned genetically to categorize things or is that just something that we [inaudible]?
Well there's stuff like social identity theory which seems to exist cross culturally, so the answer is probably "partially, yes". We do seem to naturally incline to certain group identities that we are then susceptible to showing (often undue) preferences for.
AM: I think it’s because so much of our society depends on the gender differences that we’ve created, and it’s almost subconscious how much we get invested in the systems that we already live in. It’s hard to imagine a system that wouldn’t have such divergent gender roles, and it scares people. I think people are kind of naturally conservative.
Is "I think people are kind of naturally conservative" exactly the sort of attitude this panel (erroneously) condemn in evolutionary psychology? I think it is.
SZ: If we’re trying to figure out what a society without gender roles would look like, it’s really hard for us.
OK, why? Might that speak to our natural history at all?
Audience question 3: Would it play biologically, though? That’s the question, mostly. I mean, would we attribute something in our brains to a society that wouldn’t have it versus a society that would.
SZ: It’s really hard to say. The thing is where we see differences, we tend to come up with reasons for differences. So if we have differences between genders that are held up by societal expectations, we living in that society may be relatively blind to all of the societal norms that are around us, but we still see that there are differences. We see that these people do this thing and these people do this thing – and this applies to way more than gender – and we come up with reasons for that.
Some of them aren’t very good. Some of them – Social sciences are not exactly still not exactly in in their infancy, but–
PZM: You bring up an important point there. This is a criticism that’s been levied against evolutionary psychology for many, many years. There is this human trend to want to find explanations, even if you don’t have a good one. You know, you want there to be a reason why your Uncle Fred died, and it can be God or it can be genes or it can be whatever. But we’ve got to have some kind of explanation.
Ergo ... a search for understanding? Inquiry? Science? I mean, in what way is this a problem in and of itself?
GL: So how did that drive benefit our hunter-gatherer ancestors on the savannah?
SZ: I’m not sure that it did, because we seem to do it even more when those differences cause problems. When things are in a particular way that causes problems, that cause particular people pain, we actually do more work to explain them because, well, they wouldn’t be there if there wasn’t a reason.
I mean basically what we are looking at here is the roots of the psychology of tribalism. Amongst primates humans seem to be overwhelmingly prodigious at cooperation, but we clearly still possess certain tribal and aggressive instincts.
Now there's a whole host of competing ideas about the context and adaptive value of aggressive strategies and tribalistic thinking related to times of conflict or austerity, just as there are a whole host of ideas about our ability to tolerate and cooperate based on other circumstances.
Its a big confusing topic. We certainly do have some behavioural propensities that are disturbing and intolerant in nature, and they exist alongside other propensities to empathise and behave altruistically.
AM: Sometimes just when they’re completely random. Definitely, to speak to a completely random gender difference, the association of pink with girls and blue with boys. That evolved utterly randomly. It was just–marketers needed a color to give to boys so they could sell boy clothes and girls so they could sell girl clothes, and they picked those colors at total random.
Did they? When? As far as I know the fashions changed. This may have been down to influence of marketers that was provoked by non-arbitrary decision making.
AM: And now you’re actually seeing evolutionary psychologists trying to come up with reasons that our brains are wired by our hormones and our genes for boys to prefer blue and girls to prefer pink.
I've not seen evolutionary psychologists do such a thing.
I've seen a pair of neuroscientists do such a thing. I quote myself from a previous post:
I know of one study, carried out by Professor Anya Hurlbert and Dr Yazhu Ling of Newcastle University that speculates loosely along such lines. Neither of them identify as evolutionary psychologists. Professor Hurlbert’s field is neuroscience. They cede that the only certain factor in colour preference is sociocultural, but speculate as to other factors including evolution. As far as I know their work has not made much positive impact on evolutionary psychologists. Whilst changes in tastes for fashion are clearly sociocultural they aren’t exclusive to notions of innate preference.
AM: But that gender differences was only invented by marketers who realized that they’d sell more clothes and toys if they gender-differentiated them.
And why did they realise that? Was it because of propensities which might be explained through examination of our natural history?
IV: I just want to get back to one of the other points that the participant was making, which was about categorization and our need to categorize ourselves. There is a strong pull to define yourself as in an in-group and then figure out who is in the out-group, who is threatening to me, who is my friend. And gender seems to be one way in which we can do that, we can talk about that, we can write papers about that.
OK, why? Might propensities to form groups speak to our natural history at all?
IV: Well, race used to be one way in which we would do that too, and now it’s become very taboo, for good reason. But there’s this question whether, if it wasn’t taboo, we would be doing all these studies about racial differences in evolutionary psychology or in anatomy. And I’m not sure, I just think that’s something that we ought to think about, about how much of our categorization is cultural. It’s cultural. It’s not necessarily in our neuroanatomy.
To try and nip this line about race in the bud. Evolutionary psychologists think we are psychologically equivalent to ancient humans BECAUSE they recognise that we are psychologically equivalent across races.
So by all means worry about certain problems relating to evolutionary psychology and sex difference - because yes, a few are supposed and we have to be careful about this sort of thing.
But the repeated charge of racism simply will not stick to all but a few practitioners on the fringes of the field.
AM: I can predict with 100% certainty, if it wasn’t taboo, we’d be seeing a slew of more IQ papers on blacks and whites.
SZ: And they haven’t gone away. They’re still being done.
GL: No, we do see it. We just don’t read those journals cause they’re boring.
IV: They don’t make it into The New York Times.
Again, I very much doubt that evolutionary psychologists are representative of those who write such papers, and those who are are not representative of the field.
SZ: [points] Yes.
Audience question 4: Two things: One, a really interesting thing about the pink is for girls, blue is for boys things is that that actually changed. Pink was originally associated with boys because it was like blood, whereas blue is just the sky, and all girls can have the sky, and then it ended up switching for some reason.
It's a separate phenomena to the one discussed by the neuroscientists - who aren't evolutionary psychologists, but just to fight their corner for a second...
The colour you chose to associate with a given gender is one phenomena.
The colour you prefer to other colours is another phenomena.
They may overlap. There may be good sociocultural reasons for why they overlap. But they are not the same thing.
Audience question 4: And I was also wondering, there have been changing differences between the gender line between males and females and what things are associated with what. How much a factor do you think the amount of hormones, like birth control or other such things that have become a lot more popular recently have affected this? Or do you think it hasn’t had any effect?
GL: One interesting observation could be made – that’s a good question – is that birth control pills probably, in a sense, mimic the environment of evolutionary adaptiveness...
...in the Serengeti that we’ve been talking about.
Which isn't the same EEA that evolutionary psychologists talk about.
Because in the absence of industrialized, effective, chemical birth control, lactational amenorrhea keeps women relatively infertile. So a woman who has a baby then lactates for a long time and, through various other traditional ways, doesn’t have a baby for four or five or six years among hunter-gatherer groups. So not having a period for six or seven years and then having a period for a few months and getting pregnant is probably kind of more normal than having a period every month for several years. So in a way, ironically, the birth control pill may actually make for a biologically less-risky, more-normal setting in terms of hormones and so forth.
I beg to differ! Just because breastfeeding and taking the pill seem to produce certain equivalencies it doesn't make them equivalent.
AM: And the research that has been coming out sort of suggests this. They’ve been doing research that shows that, because women tend to pace their children a little bit better than they did 50 years ago, you’re seeing bigger brain sizes, better nutrition in the second child than you would. It’s just kind of interesting.
PZM: Plasticity everywhere. I think that would be really the message of anybody who wants to oppose evolutionary psychology–is they downplay the importance of developmental plasticity.
SZ: Do we still have a question? No. Let’s take one here. Jason.
Audience question 5: I just want to say that there are evolutionary psychologists who are still making these racist cases [inaudible]
PZM: Satoshi Kanazawa, yes.
SZ: Who is an economist. I wasn’t kidding about economists doing “evolutionary psychology.”
He's an evolutionary psychologist who reads in management at the London School of Economics. I don't see why such things are mutually exclusive.
He's also discredited and widely seen as an embarrassment to the field, though I see this does not get mentioned.
AM: It comes up periodically, like some conservative think tank will just cough up a writer who says, “We need to study the IQ differences between blacks and whites more.” And then Andrew Sullivan will always back him up. Then a bunch of scientists will come out and say, “Bullshit,” and then it will die.
Then it will come up every few years. We had it this year, so we’re due in 2016, I think.
To repeat - this is nothing to do with mainstream evolutionary psychology which supposes that all modern populations are equivalent in terms of psychological capacity and that that's the way things have been for thousands of years.
GL: One of the recent developments there has been something that happened– This actually happened since the 19th century. This is sort of how the British did their whole–British invasion theme? [callout to the theme of the convention]–you know, colonizing the world. Some cultures and some countries are simply smarter than others. This has come up a few times.
It came up several years ago when Robert Klitgaard on why African countries are corrupt. It’s innate corruption. He actually came to me. He was referred to me to talk to an anthropologist about support for his book and how this would work genetically and so on. It was pretty interesting listening to that conversation. But the same place, think tank, Kennedy school, which is a pretty liberal place normally, has come out recently with some research on comparing countries’ IQ. There’s actually a paper coming out in a few months or so in Current Anthropology that will be addressing that claim in those books, and it will be a very interesting – there will be a big controversy when it comes out.
PZM: So there’s, like, a corruption gene perhaps? A corruption module in the brain?
I don't know, but to turn it around would you deny innate factors which might impact on someone's ruthlessness?
Now for a long tangent with scant pertinence (and no apparent reference) to the purported topic of discussion:
AM: I think this brings up the question: I think a lot of people do assume IQ is genetic, but that’s certainly not true, is it?
IV: Well, you know, how do you measure IQ? It’s “intellectual quotient”, right? It’s so culturally specific in so many ways. Is it vocabulary? Of course, we as psychologists come up with many different ways of measuring it, and we try to make it cross-cultural, but it’s extremely hard. And no one’s come up with a great measure that doesn’t change with time, so if you look at IQ over the course of the last 100 years in the U.S., it’s gone up, and it’s gone down, depending on how you measure it. Of course, what’s happening is that people are getting better at testing, or they’re getting more exposed to whatever it is that the testers are measuring. So they create new tests that have better measures.
It’s such a general thing that it’s difficult to get an answer to that.
GL: If you actually trace back the IQ papers that keep coming out, they all go back to an original literature that was kind of congealed by Philippe Rushton and which refers to a series of studies on IQ which includes two of our favorites. One, which was done at Yerkes Primate Center for a contract for the army. In the early version of Yerkes, there was a contract for conscripts determining which conscripts should get training to become officers and so on in the largely non-literate society of the time of World War I. So this was a non-literate IQ test.
That non-literate IQ test was given to girls in a school in Zululand in South Africa in the 1950s as a part of an apartheid government’s directive to scientists to prove the inferiority of black people. And these girls got an IQ rating of about 70. This included–one question they all got wrong was showing two people, stick figures, two people wearing tennis whites with tennis racquets and no net. And they were being asked, “What is missing in this picture?” That was on the test, and none of them knew.
I used to give my students a test that was similar. I would show two men standing there with obviously a Zulu warrior shield and a spear–one man standing there was a Zulu warrior shield and a spear, and it was from a Zulu ceremony. “What is missing here?” And it’s the guy pretending to be a lion. [laughter] You didn’t know that?
So that IQ test showed that Africans have IQs of 70. Philippe Rushton knew, somehow, that African Americans had a 20%/80% white/black admixture, and then he saw this persistent and largely environmental difference in kids in schools and getting IQ rankings of about 20 points difference and explained that as a genetic admixture. And that is a convincing argument that IQ is genetic that is ultimately referred back to by every paper–first another paper and another and ultimately to this one study that links these things together, which has been debunked and thrown out.
Not to mention, Rushton linked it to brain size by having black in his sample have small brains by taking the measured brain size using hat measurements from conscripts in the army, estimating the brain size, and then reducing the black brain sizes by a certain percentage in every case because Africans have thicker skulls–which they don’t. He based that on using the Bodo specimen, which is a Neanderthal. And then he adjusted all of his – So that’s where Rushton’s race concept comes from, that blacks have small IQs because of hat-size measurements with simply something subtracted from every measurement if you’re black because we assume you have a thicker skull.
AM: And then there’s the great irony there that they’ve discovered that it’s white people that have more Neanderthal in them now.
GL: And also a thicker skull. Old skeletons from African tend to have thinner skulls.
SZ: I see a lot of shaking heads out there. Any time you think, “No, they couldn’t have done something that bad,” somebody did.
IV: I think the moral is, if you ever have a study that talks about IQ, you really have to look at how they measured it, because it is so controversial in the psychology literature.
Once again - sorry for the repetition - evolutionary psychology works on a general assumption that the races are equivalent in terms of psychological capacity. IQ isn't therefore of a great deal of interest, because performing well in tests in IQ is partially a learned skill.
SZ: [points] Debbie.
Audience question 6: What are the good parts of evolutionary psychology? [laughter]
PZM: That’s a really hard question.
AM: I like the jokes that the actual biologists make about them behind their back.
IV: And I think they tell really good stories. They take something that’s really complicated and they distill it out, and they make it a good story. And I think that sometimes, by doing that kind of theorizing, we can develop a better model for what we want to study and what we want to look at. The problem comes when we take that as fact and then stop there instead of saying, “Hey, that’s an interesting story. Let’s go test it.”
So is Indre saying that they don't do tests or something? I don't really understand this. Seems to me they talk an awful lot about tests.
SZ: Yeah, the problem isn’t what kinds of things they came up with. The problem is that they’ve done all this research that either only supports it if you don’t pay any attention to what somebody over there is doing or contradicts their own theory, and they haven’t thrown anything out.
Actually I think this degree of "throwing out" occurs pretty rarely in science:
In light of the recent furore surrounding Satoshi Kanazawa's Psychology Today blog post ["Why Are Black Women Less Physically Attractive Than Other Women?"], we feel compelled to state publicly that Kanazawa‟s research should not be taken as representative of the evolutionary behavioural science community. Kanazawa's blog post generated enormous media attention, including the BBC‟s flagship News at Ten programme. It also attracted considerable comment from the online community, much of which was highly critical of the discipline of evolutionary psychology which he claims to represent. As a result, Kanazawa's home institution, the London School of Economics, will be hosting a debate this week on "Is evolutionary psychology racist?". Yet a large number of scientists who apply an evolutionary approach to human behaviour consider Kanazawa's work to be of poor quality and have demonstrated this via their own academic critiques. He has repeatedly been criticised by other academics in his field of research for using poor quality data, inappropriate statistical methods and consistently failing to consider alternative explanations for his results.
We have previously pursued the usual scientific channels open to us to counteract what in our view is Kanazawa's poor quality science by reviewing and rejecting his papers from scientific journals, and by publishing critiques of his papers in the scientific literature. This has not stopped him from continuing to produce poor quality science and promoting it directly to the public. We have therefore taken the unusual step of making this statement to counteract the damage we believe he is doing to the perception of our discipline in the media and among the public. The principle of applying evolutionary theory to the study of human psychology and behaviour is sound, and there is a great deal of high-quality, nuanced, culturally-sensitive evolutionary research ongoing in the UK and elsewhere today (see for example the European Human Behaviour and Evolution Association, which actively aims to promote rigour within the field).
It goes on to give more details and is signed by 68 evolutionary psychologists. It's the sort of rejection that actually doesn't occur that often in science, as far as I can see.
AM: I will say, I will give them credit for this one thing. They have popularized the notion in the popular consciousness that our evolution impacts who we are, and that’s actually true. I think it makes explaining certain other concepts, like when you’re trying to explain cognitive biases to somebody and why our brains kind of trick us into seeing things that aren’t there or misunderstanding something, I think that makes it a lot easier for an American audience to understand that, because unfortunately, it was evolutionary psychology that primed the well.
GL: There’s actually some good studies, some good evolutionary psychology studies that people who claim it help [inaudible] have done. Just go to the UCLA department of anthropology and look at Dan Fessler and Boyd and so on, [inaudible]. There’s a handful of people there doing interesting work. Some of it basically has to do with proclivities and things, interesting tests where you can find out that humans react to certain environmental cues in certain ways consistently. The underlying theory that these are evolutionarily shaped sets of genes that inevitably lead to these outcomes is still in there, and this is still probably wrong.
Why? If we have a predictable reaction to environmental cues what else could be responsible for it other than our neurology and what else builds our neurology besides genes?
GL: Because evolutionary psychologists started out with a really interesting hypothesis that they then assumed was just true, and it’s never been tested, which is that we have genes that shape modules and that those genes are under selection because the modules are where the rubber hits the road in a selected milieu. And that’s never been tested. The modules may still well exist in adults, and they’re doing some interesting studies in places like UCLA looking at those modules and identifying and defining them. And it’s interesting, but it just doesn’t really prove the point that you have this EEA in which genes are shaped and so on.
PZM: Boy, I would categorically say that there aren’t any good evolutionary psychology studies. I know that’s really harsh of me, but I think it’s the case. What there are though are good people within the field who go back to basics and do good work. For instance, there are people like Sarah Blaffer Hrdy who does a lot of cultural anthropology. I think it’s phenomenal stuff. She’s actually looking at the evidence and not making ridiculous assumptions from it. Often when you read her papers, what you find is she’s testing some assertion made by evolutionary psychologists and finding it’s wrong. So I guess that’s our guideline. If they find something wrong with evolutionary psychology, they’re good people.
But Sarah Blaffer Hrdy says loads of stuff which is basically evolutionary psychology 101. Three quick examples of her basically saying the same sort of things the panel have found objectionable up to now.
Custom, language, and personal experiences shape the specifics, but the urge to share is hard-wired, and neurophysiologists are getting to the point where they can actually monitor, if still only crudely, the pleasure humans derive from being generous, helping, and sharing.
- Mothers and Others, page 25.
The pertinence of the Pleistocene:
We are told again and again that "the human ability to generate in-group amity often goes hand in hand with out-group enmity." Such generalisations are probably accurate enough for humans where groups are in competition with one another for resources, but how much sense would it have made for our Pleistocene ancestors eking out a living in the woodland and savannahs of tropical Africa to fight with neighbouring groups rather than just moving?
- Mothers and Others, page 19.
The fact that humans are better equipped to cooperate than other apes does not mean that men do not compete with one another for status or for access to mates, or that women are not fiercely competitive in the domains that matter to them, striving for desirable mates, local clout and access to resources for themselves and their children.
- Mothers and Others, page 11.
So to treat her, as PZ does, as some kind of iconoclast is silly. She does present some challenges to those who have gone before her, but so do Pinker and Buss and Tooby and Cosmides (all of whom she references in this book).
Now this isn't to say that she doesn't take on a few sacred cows, for example she raises a serious challenge to attachment theory, but it wasn't a cornerstone of evolutionary psychology, it was more of a psychoanalytical concept which had already come in for some hard criticism.
GL: Don’t assume evolutionary psychology and human behavioral biology are the same.
Ultimately I'd say that a Venn diagram of the territory claimed by the two fields would show far more overlap than areas of exclusivity.
GL: Sarah’s not an evolutionary psychologist. She’s a behavioral biologist.
PZM: That’s what I mean. Where you find good scientists, who often get appropriated by evolutionary psychologists within their field, is they’re doing more fundamental research. I would also recommend people like Robert Sapolsky, who is looking at the effect of hormones on the brain and looking at evolution of primates and things like that. There’s a lot of good stuff out there that sort of fits within this domain. The question of how did the brain evolve is a legitimate one. It’s a good one. It’s just that I think that the premises of evolutionary psychology so taint the field that it’s basically a dead end that ought to be discarded.
As Robert Kurzban notes:
He hates what he thinks evolutionary psychology is. Actually, there’s evidence he likes the field. Take, for instance, his view of Sara Hrdy’s work. Hrdy has played an active role as an officer in the Human Behaviour and Evolution Society (HBES) and was recently awarded the Lifetime Achievement Award by this group, which is arguably the world’s leading collection of evolutionary psychologists. Wikipedia calls Hrdy “an American anthropologist and primatologist who has made several major contributions to evolutionary psychology and sociobiology.” (That’s Wikipedia, not me, placing her in these categories.) Indeed, here she is in this picture taken at the recent HBES conference – organized by Deb Lieberman and Mike McCullough – smiling next to Doug Kenrick, Leda Cosmides, and Steven Pinker, among others. If she’s not at the epicentre of evolutionary psychology, it’s hard to know who is.
AM: You know, its one of the interesting things I kind of want to point out. I often, very frequently, get requests to debate an evolutionary psychologist in a public forum, and I always decline and offer to refer them to a biologist who is willing to debate them. And they always take a pass. And I think that’s very telling – that they want to debate a journalist, somebody with no PhD, no science background, who likes science but doesn’t really understand it to the same extent that the rest of the people on this panel do. That’s just something I want to put in your brains.
As Ed Clint notes in the comments:
It may not be strange that evolutionary psychologists declined Marcotte's alleged offer, but the unsaid details matter. If such a person read Marcotte's outrageous slander of their science, subsequently issued a debate challenge and were then told "No thanks, but will you debate this other person who hasn't made the absurd claims I have instead?" I think such a person would reasonably be inclined to say no.
Her admission is also damning of her character: she is willing to make strong, uncited pronouncements deriding a large scientific enterprise, but when challenged is suddenly a hapless amateur who can't be expected to engage. Just so that readers know the sort of claim I am referring to, Marcotte tweeted "Skepticism of evo psych isn't "anti-science" anymore than skepticism of phrenology is. Meh."
Robert Kurzban also has some interesting things to say about Marcotte.
In short, Marcotte doesn’t understand the most basic assumptions that underlie the field, which have been made very explicit in many places. Instead, what’s happening here is that she’s relying on her intuitions about what a field called “evolutionary psychology” is trying to do, which is why she thinks it’s about showing that behavior is genetic as opposed to learned. As something of an aside, note that she thinks that psychologists “prove” things, an incorrect impression many of us are able to suppress in our first year undergraduate students in introductory psychology classes. There is a sense in which her ignorance of the way science works, generally, works against her narrower claims because of the credibility that it costs her.
PZM: One of the things that you notice about popular evolutionary psychology is that it’s often simply fodder for tabloid journalism. That’s where their brains are at. There’s something adapted there. Anyway.
So when you read the stuff that makes it in the popular press, it’s always about similar sorts of things. IQ studies get mentioned a lot, particularly catered to populist biases that the blacks or the immigrants are dumber than the good native people. If it’s about women, it’s about how women are passive or sexual aggressors or sexual weirdos, and men are the dominant ones.
I'd love to see the study performed by evolutionary psychologists to the end that women are "sexual weirdos". At this stage I call shenanigans. Anyone got a link to prove me wrong?
PZM: They constantly play up these sorts of differences because that stuff gets rewarded with notice in the press. And it’s really unfortunate.
Good studies, like I mentioned Sarah Blaffer Hrdy, who’s got a whole book on, for instance, the maternal instinct and basically shows it’s a bunch of bunk, that women do not have any sort of maternal instinct – that didn’t make it into the press for some reason. Not a feel-good sort of story that fits into our notions of motherhood.
I would say it is a vulgar piece of hyperbole to suggest that she makes the claim that the maternal instinct is "a bunch of bunk" and that women entirely lack any such thing.
What she does assert is that ancestral humans cooperated more in regards to rearing children than is popularly assumed. This does not imply a lack of maternal instincts in the mother, it implies previously underappreciated alloparental instincts in other members of the community.
Here are some examples that run counter to PZ's claim taken from pages 38 to 41 of Mothers and Others, the Evolutionary Origins of Mutual Understanding:
The postpartum human mother who checks her baby every 15 minutes to be sure he is still breathing follows in this venerable tradition of compulsive concern.
Since any nearby new-borns were likely to have issued from their own bodies, it was adaptive for mothers to perceive all neonates as attractive. Mothers who had just gone through the hormonal transformation of pregnancy were especially susceptible.
This requirement for mothers to bond with babies, and babies with mothers, meant that mammals' brains were designed for the formation of relationships in ways that the brains of other animals are not. The need for mothers to anticipate the needs of offspring is integral to several of the hypotheses that have been proposed to explain the evolution of mind reading.
To me - this sort of stuff lies a long way from "the maternal instinct is bunk". Unless Sarah's beliefs have taken a wildly divergent turn in the last few years (Mothers and Others was published in 2011) I think it would be fair to say she recognises quite profound innate propensities for mothers to identify and care for their children. Her main contention in the book is that such feelings are shared to some degree by friends, family and neighbours. So it's not that women lack a maternal instinct, it's that the rest of us have one too, to some degree.
GL: It’s funny that we keep circling around to class. Even the sex differences is a class issue, because most of this research, historically – sex differences have been supported and asserted by men, who are the higher-class sex when it comes down to it, economically and power relations and so on. It’s not even biology.
PZM: This is a common theme in many of these popular evolutionary psychology articles too, is that women are the passive recipients of the male genetic heritage. There was this recent thing. Maybe you’ve heard about the menopause study?
AM: Yes, I stomped around my apartment for about five minutes after reading about that.
PZM: Yes, men did it to women because women have absolutely no control over their reproductive impulses.
As Robert Kurzban notes:
This paper wasn’t, however, written by evolutionary psychologists or anthropologists, but rather the good guys in Myers’ world view: biologists (at McMaster, in this case). The paper did not appear in one of the field’s journals, but rather in PLoS. I don’t have a particular view about the work, and I suppose by some stretch it could count as evolutionary psychology, but only by a stretch, and the work seems far more distant from the centre of the discipline than, say, Hrdy’s work.
AM: Yeah. The theory was that men basically induced menopause into women by stop having…by stop fucking them, basically once they get too old to be attractive anymore, which apparently hits you at, what, I guess 45, 50 in their theory.
GL: Well, that explains why it’s called “menopause.”
PZM: And if you read the study, there’s absolutely no data to it. It’s entirely a mathematical modeling study, where they’re basically saying, “Hypothetically–”
SZ: “If we make these assumptions–”
PZM: Yes, we can generate a model in which women go barren after…
AM: I always like to tell myself– If they’re going to tell just-so stories, I tell just-so stories about the scientists’ motivations for this. And the ones I told myself after reading that were pretty great.
SZ: All right. We are technically out of time, but if any of our panellists have any last words that are quick last words?
IV: I would just like to point out, though, that there is a resurgence in the interest in the relationship between genes and behavior. And I think it’s one that is really well worth studying, particularly in an area that is being fired up about it right now, which is dementia. You know, we’re facing this huge problem in a few years, where the number of people with dementia is just going to be unbelievable. And yet, it turns out that there is some genetic component that we can start to study, and that by treating particular people with genetic changes, we might be able to find a cure for some subtypes of dementia. So there is a hope that eventually we’re going to find more links between genes and behavior and then be able to use them to make our lives better.
PZ: I’ll agree with that. There is a sound basis, a material, biological basis to how the brain works, and I agree 100% with that. And I will say that even I am doing research on genes and behavior in my lab, but I do it on fish, where you can do real experiments. Come on.