Now that David Brooks has endorsed it, can we declare evolutionary psychology brain-dead and pull the plug?

This is a doozy of a canard that just won’t die. It’s how idiots who don’t understand evolution, but know that the theory is highly esteemed by scientists, attempt to coopt Darwin to be the figurehead for racism and sexism.

The Cultural Marxist War against Darwinism

Creationists: evolution is a social construct, not biologically real.

Liberal Creationists: race is a social construct, not biologically real.

Charles Darwin: I’m not a creationist: I’ll use the word ‘race’ in title of my Origin of Species

It’s the dumbass dichotomy: you will either believe in their crude, ill-informed, cartoon version of biology that says that black people are different and inferior, or you’re a creationist. It’s false. The argument is rotten all the way through. Not only do I reject the premise as ill-informed and wrong, but I also reject it because it’s a blatant attempt to commandeer science to be their banner.

It’s bad enough that racists play this game, but guess who else does it? Evolutionary psychologists. Evolutionary psychologists are just the worst.

So I got called out by Lilian Carvalho, a professor of marketing at a business school who studies consumer behavior and — what else? — evolutionary psychology. I have to revise my previous statement: evolutionary psychologists who think their crude misunderstandings of how evolution works gives them a handle on consumer behavior and marketing are the worst of the worst.

Anyway, Carvalho twitted this:

Another false dichotomy, common to evolutionary psychologists! You see, if you don’t accept their adaptationist model of how the human brain evolved, with every quirk and kink selected to be optimal for life on the savannah 10-100 thousand years ago, then you think biology only works from the neck down. They like to set themselves up as the sole arbiter of how brains evolved, when they always seem to have such a poor grasp of evolution in general, and usually are just coming at it in defense of the biases of the status quo.

I took a look at her twitter history before blocking her, and oh, yeah — it’s full of familiar names, “scientific” racists and anti-feminists and marketing professors, basically a collection of third rate ignoramuses puffing themselves up by waving Darwin around as their virtue signal. Ugh. I don’t need that crap in my life.

But then I read…David Brooks. Fuck me sideways, but we’ve found the worst of the worst of the worst.

Like all the EP wackaloons, he’s irate over the James Damore affair — he argues that Damore shouldn’t have been fired, because he was correct about the biology (which raises the question…how would a conservative pundit with no qualifications for anything know?), but that the CEO of Google, Sundar Pichai, ought to be fired for joining the mob. Of course, he cites evolutionary psychologists as saying Damore’s manifesto was scientifically accurate when the truth is that an evolutionary psychologist wouldn’t recognize scientific accuracy if it bit him in his bright pink berries.

I hit this paragraph and was stunned at the magnitude of the dishonesty and inanity.

Damore was tapping into the long and contentious debate about genes and behavior. On one side are those who believe that humans come out as blank slates and are formed by social structures. On the other are the evolutionary psychologists who argue that genes interact with environment and play a large role in shaping who we are. In general the evolutionary psychologists have been winning this debate.

Whoa. Brooks sets up two strawmen, labels them incorrectly, stages a battle in his head, and declares the victor.

Look, guy, the nature/nurture debate is dead. Any time I see someone setting up an argument with this hoary ancient dichotomy, I know I’m dealing with an uninformed nitwit. But to characterize it as Brooks has done is carrying idiocy to an absurd degree.

And then…the blank slate. Good god, I blame Pinker for reviving this bullshit and using it to slander his scientific opponents. No one believes the human mind is a blank slate. No one. I’m probably as liberal as most scientists come, you can call me a SJW and I don’t blink an eye, and you won’t find me claiming that. I believe we carry all kinds of predispositions (like a tendency towards tribalism…) that are consequences of our biological nature. I know there are biological differences between men and women, but I also know that people like to falsely rationalize behavioral differences as somehow innate and genetic. That first straw man is basically a nonexistent cartoon.

His second straw man made my jaw drop. evolutionary psychologists … argue that genes interact with environment…unbelievable. The standard understanding among all knowledgeable biologists is that organisms are products of genes and environment interacting; you can’t tease the two apart. That’s why the nature/nurture debate is archaic nonsense. What Brooks has written there is not the key property of evolutionary psychology. It’s what actual evolutionary biologists think.

Evolutionary psychologists believe that the human brain evolved in a specific environment over 10,000 years ago, and that all of the features of how our minds work can be described as adaptations to that environment. It is profoundly dishonest to appropriate the mainstream understanding of the role of genes and environment and credit it to a pseudoscience, while leaving out the actual premises of that pseudoscience. Evolutionary psychologists emphasize the primacy of genetic explanations; they argue that human behavioral traits — how well we do at math, who is most suitable for working in computer science — are affected by a legacy of genes we inherited from our paleozoic ancestors, and that they have the tools to determine exactly which traits are adaptive products of our past. They don’t. They’re masters of the panadaptationist just-so story, nothing more.

And then Brooks declares that the evolutionary psychologists are winning. But he’s just used a bogus definition of evolutionary psychology, one that is more appropriate to real biologists, and pretended that their opponent is a caricature, the blank slater.

Man, those two straw puppets just whaled the hell out of each other.

Yet people are citing David Brooks as the voice of reason all over the place — even Steven Pinker retweeted it. Wait. Of course Pinker would retweet that pile of crap.

James Damore was speaking bullshit calmly, so I can sort of understand David Brooks approving of it, as a kind of professional courtesy among bullshitters. But if you know anything about the science, you shouldn’t accept these lies.

Science doesn’t say that biology holds women back in the workplace. What Damore and Brooks have written is the same old exhaustingly familiar apologetics for discrimination. It’s not science, it’s prejudice pretending to be science.

And right now, evolutionary psychology is the field of choice for bigots who want to pretend to be scientists.

A new challenge for Evolutionary Psychology!

The berry-picking stuff has been done to death — and I haven’t even gotten to blueberries and tubers — but here’s an idea that ought to be pursued. What is the evolutionary and genetic basis of different ways of buttoning shirts? It’s a consistent pattern, has been that way for centuries, so by EP logic, there is surely a button-handedness module or gene.

Once they’ve figured that one out, they should get to work on pockets. That’s an infuriating sex difference.

History will judge evolutionary psychology as the phrenology of our era

I’ve criticized evolutionary psychology more than a few times, and usually my arguments rest on their appallingly bad understanding of the “evolutionary” part of their monicker — proponents all seem to be rank adaptationists with a cartoon understanding of evolution. But what about the “psychology” part? I’ve mentioned at least one dissection of EP by a psychologist in the past, but here’s another one, a paper by the same author, Brad Peters, that explains that evolutionary psychology is poor neurobiology and bad psychology.

The paper points out that EP uses evidence inappropriately, ignores the range of alternative explanations to set up false dichotomies (“if you don’t accept evolutionary psychology, you must also deny evolution!”), plays rhetorical games to dodge questions about its assumptions, and basically is pulling an ideologically distorted version of neuroscience out of its institutional ass.

Evolutionary psychology defines the human mind as comprising innate and domainspecific information-processing mechanisms that were designed to solve specific evolutionary problems of our Pleistocene past. This model of the mind is the underlying blueprint used to engage in the kind of research that characterizes the field: speculating about how these innate mechanisms worked and what kinds of evolutionary problems they solved. But while evolutionary psychologists do engage in research to confirm or disconfirm their hypotheses, the results of even the most rigorous studies have been open to alternative, scientifically valid means of interpretation. What constitutes “evidence” would seem to vary in accordance with the theoretical assumptions of those viewing it. Arguments about, or appeals to, “the evidence” may thus involve little more than theoretical bible-thumping or pleading for others to view the “facts” from their preferred theoretical perspective. When theoretical paradigms are unable to agree on what it is that they are looking at, it reminds us that the data are anything but objective, and gives good reason to question the theoretical blueprints being used. This paper argues that evolutionary psychology’s assumptive definitions regarding the mind are often inconsistent with neurobiological evidence and may neglect very real biological constraints that could place limits on the kinds of hypotheses that can be safely posited. If there are problematic assumptions within evolutionary psychology’s definition of the mind, then we also have reason to question their special treatment of culture and learning, since both are thought to be influenced by modular assumptions unique to the paradigm. It is finally suggested that the mind can be adequately understood and its activities properly explained without hypothetical appeal to countless genetically pre-specified psychological programs, and in a way that remains consistent with both our neurobiology and neo-Darwinian evolution. While some of these critiques have been previously stated by others, the present paper adds to the discussion by providing a succinct summary of the most devastating arguments while offering new insights and examples that further highlight the key problems that face this field. Importantly, the critiques presented here are argued to be capable of standing their ground, regardless of whether evolutionary psychology claims the mind to be massively or moderately modular in composition. This paper thus serves as a continuation of the debate between evolutionary psychology and its critics. It will be shown how recent attempts to characterize critiques as “misunderstandings” seem to evade or ignore the main problems, while apparent “clarifications” continue to rely on some of the same theoretical assumptions that are being attacked by critics.

Another valid criticism is how evolutionary psychologists seem to be unaware of how the brain actually develops and works. Anybody who has actually studied neurodevelopment will know that plasticity is a hallmark. While genes pattern the overall structure, it’s experience that fine-tunes all the connections.

The current consensus within the neurobiological sciences seems to support a view where much of the brain is thought to be highly plastic and in which an abundance of neural growth, pruning, and differentiation of networks is directly influenced by environmental experience. This is especially the case for secondary, tertiary, and associational areas, which make up the majority of the brain’s neocortex and are primarily involved in the kinds of complex, higher-order, psychological processes that appear to be of greatest interest to experimental psychologists. These particular areas seemingly lack characteristics indicative of innate modularity, though, with experience and use, they may build upon the functional complexity of adjacent primary cortices that perhaps have such characteristics.

I also like that he addresses a common metaphor in EP — floating free of good evidence, much of the field relies on glib metaphors — that we can just treat the brain like it is a computer. It may compute, but it’s not very analogous to what’s going on in your desktop machine or phone. We aren’t made of circuits hard-printed by machines in Seoul; there is a general substrate of capabilities built upon by the experiences of the user. Further, we’re not entirely autonomous but rely in the most fundamental ways on by growth and development, sculpted by culture.

We can see the problem from a different perspective using evolutionary psychology’s favored computer analogy. While it is true that humans have some engrained and preprogrammed biological circuits, all evidence would suggest that, unlike modern computers, our environmental experiences can cause these mental circuits to become edited, hi-jacked, intensified or lessened, inhibited, and so on. How else might we explain a person acquiring a phobia of hats, a fetish for shoes, or having an apparent indifference to what might be an evolutionarily relevant danger (e.g., cliff jumping)? If we accept this is true, we must also accept that it becomes difficult to say what might have been there at birth, or instead shaped by common environmental experiences that we all share. Modern computers cannot be re-programmed without a human; they do not function like the human mind. We are the ones who effectively tell computers what the binary ones and zeros of their programming language will represent. We give symbolic meaning to the code, which allows us to even say that computers processes information. Now let us turn to the human mind. Evolutionary psychologists want to say that meaning and information are objectively pre-programmed by our inherited biology. However, it would appear that we extract much of our information, and the meaning it contains, from a sociocultural cloud of symbolic representations that belong to a shared human subjectivity, or something Raymond Tallis refers to as the community of minds. Our subjective mental states are thus socioculturally structured and shaped through our reliance on an agreed-upon language and agreed-upon sets of subjective human meanings. The brain is only one part of the picture: it facilitates the mechanistic activities of the mind, but it does not solely cause them. Human meanings, which belong to the collective community of minds, will thus often transcend the underlying mechanisms that represent them.

Wait. If the “evolution” part is crap, and the “psychology” part is bullshit, what’s left in evolutionary psychology to respect?

Peters, BM (2013) Evolutionary psychology: Neglecting neurobiology in defining the mind. Theory & Psychology 23(3) 305–322.

Here we go again: another cock-eyed defense of evolutionary psychology

This Myles Power guy fished up an evolutionary psychologist to write a defense of of EP, which is not at all impressive. I’m sure he could also find an acupuncturist to write many words about the wonders of sticking needles in people, but I wouldn’t be impressed with that, either.

I will just point out that this fellow also has decided that everyone who criticizes EP is ideologically motivated to hate it; it can’t possibly be that we detest it because it is bad science. And of course he pisses me off with his dishonest opening.

Now, before I begin, ask yourself this, if you are against EP, why? Which of the following do you disagree with:

  • Evolution shapes both the morphology and behaviour of organisms
  • Humans are as much a product of evolution as any other organism
  • Humans behaviour should show evidence of being shaped by evolution

Because if the answer is, “well, none of them”, then there is really no need to go anything further. Because that’s all EP is in the end, looking at humans from the point of view of evolution. It’s taking 150 years of evolutionary theory and applying it to human behaviour. That’s it. We can discuss the impact any evolved pre-dispositions have on behaviour in the context of social, cognitive and biological perspectives without name-calling. So we’re good yes?

No. We’re not good. This is classic EP evasion tactics: immediately hiding behind general principles of evolutionary biology, as if disagreeing with EP is exactly equivalent to denying evolution. It’s annoying as hell to every time have a chorus of idiots accusing me of being a creationist because I find evolutionary psychology to be simple-minded to the point of utter uselessness in actually explaining anything about human evolution, and it’s people like this EP proponent who always try to feed that nonsense right from the get-go.

Evolution shapes both the morphology and behaviour of organisms. Humans are as much a product of evolution as any other organism. Humans behaviour should show evidence of being shaped by evolution. Yes to all of those. Accepting basic biological facts does not, however, in any way imply that I must therefore accept the specific claims of a fallacious hypothesis about human evolution. Evolutionary psychologists are not simply applying 150 years of evolutionary theory to human behavior, and it’s dishonest to claim that they are.

I skipped the rest. If the author can’t even be trusted to explain what makes EP a specific and useful approach, but just wants to pretend it’s plain old evolutionary biology, using the same methods and rigor, then I’ve got no use for more games of hide and seek.

Myles Power’s dishonest defense of evolutionary psychology

Back around the 11th of July, I saw a few comments by a guy named Myles Power, a science youtuber, who was quite irate that Rebecca Watson criticized evolutionary psychology five years ago. There were the usual vaguely horrified reactions implying how annoying it was that some mere communications major would criticize an established, credible, true science like EP, and how she was prioritizing entertainment over scientific validity (not all from this Power guy; Watson is a magnet for the same tiresome bozos making the same tiresome complaints). So I told him that no, her criticisms were not off-base at all, and then a lot of scientists consider EP to be poor science. I also gave him a few links to consider.

He saw them, and acknowledged it.

@pzmyers This may take me some time to get back to you :)

He did not get back to me. Instead, he came out with a video titled Rebecca Watson’s Dishonest Representation of Evolutionary Psychology. It did not use a single scrap of the information I sent him. Not one bit. Furthermore, he just made this excuse.

I am also doing the ground work in organising a google+ debate with PZ and a Prof in EP from a reputable university.

Say what? He wrote that on the 14th. Not once has he contacted me about “organizing” a debate. One would kind of think that contacting both of the principals in this planned debate would be the very first step in organizing it. Do I get to say “no”, are is he just assuming that all he has to do is contact the esteemed EP professor and then I’ll self-evidently fall into line? I’m not at all impressed with Myles Power’s honesty so far.

So then I watched the video.

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I think I missed a good critique of evolutionary psychology

I must have been taking a nap a couple of years ago. I just found this interesting discussion of EP by a psychologist, and I agree very much with it.

Evolutionary psychologists believe that the human mind works much like the body… that it is an information-processing system, with pre-specified psychological programs (or environmentally-triggered ones), adapted much like the rest of the body, to meet specific problems in our evolutionary past. Others, including myself, disagree with this definition of the human mind. While I would certainly agree that evolution had a profound role in shaping lower-level modular systems, including autonomic nervous system responses, reflex arcs, immune systems, complex motor control, systems related to sexual arousal, and so on, it does not make sense for us to assume that our more complex social behaviors were shaped in the same way, or that they would even depend on lower-level domain-specific systems that evolutionary psychologists so frequently assume to be the ‘ultimate’ causes of behavior. Neurobiologists Panksepp and Panksepp point out that while evolutionary psychologists may interpret psychological data in a way to fit with their preferred theory, the philosophical assumptions that are the foundation of that theory are not at all consistent with what we know about human neurophysiology.

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Jerry Coyne is trying to defend evolutionary psychology again

Why, oh why, do EP’s defenders rely on throwing up armies of straw men to slaughter? It’s silly. Here’s how he starts:

There are some science-friendly folk (including atheists) who simply dismiss the entire field of evolutionary psychology in humans, saying that its theoretical foundations are weak or nonexistent. I’ve always replied that that claim is bunk, for its “theoretical foundations” are simply the claim that our brains and behaviors, like our bodies, show features reflecting evolution in our ancestors.

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Tackling Pinker’s defense of evolutionary psychology

I previously addressed the criticisms of my criticisms of evolutionary psychology by Jerry Coyne; Now I turn to the criticisms of my criticisms he solicited from Steven Pinker. This is getting a bit convoluted, so let me first state the basics.

I dislike evolutionary psychology. Pinker is an advocate for evolutionary psychology. What brought on this back-and-forth was that I was a member of a panel at a science fiction convention that discussed evo psych; I made a few brief comments on my blog that were capsule summaries of my discussion there. In the section below, the paragraphs preceded by an “M:” and in italics are my words excerpted from those comments; the parts preceded by a “P:” are Pinker’s commentary. All clear?

M: Fundamental assumptions of evo psych: That you can infer an adaptive history from the distribution of current traits — that they are adaptations at all is an assumption usually not founded in evidence (this is not to deny that that there are features that are clearly the product of selection, but that you can’t pick an arbitrary attribute and draw elaborate scenarios for its origins). . .

P: Of course “arbitrary” and “elaborate” are the straw-man giveaways here. What about carefully selected attributes, and minimal assumptions about phylogeny with a focus on function, as we do for other organs? You can ask what the spleen is for – and it would be perverse to do physiology without asking such a question – without “drawing elaborate scenarios for its origins.”

Whoa, whoa, whoa — that skips right over the really important word: “adaptive”. Start there. That’s my primary objection, the habit of evolutionary psychologists of taking every property of human behavior, assuming that it is the result of selection, building scenarios for their evolution, and then testing them poorly.

We already know that that is impossible. The repertoire of human behavior is so complex and rich, and relatively recently evolved, that to argue that every behavior is the product of specific selection imposes an untenable genetic load. The bulk of the genetic foundation of our psychology (and I agree that there must be one!) must be byproducts and accidents. The null hypothesis of evolutionary psychology should be that a behavior is non-adaptive, yet for some reason all I ever see is adaptive hypotheses.

The spleen is an interesting example. There are components of the spleen that are definitely functional and almost certainly adaptive: its functions as a blood reservoir, as an element of the immune system, as part of the erythrocyte cycling mechanism. You can examine the evolution of those functions phylogenetically; for instance, some teleosts lack the erythropeotic functions of the spleen, while the majority use it as a blood reservoir. You can begin to dissect its history comparatively, by looking at what has a clear functional role and looking at the pattern of emergence of those properties.

What you can’t do is pick any particular property of the spleen and invent functions for it, which is what I mean by arbitrary and elaborate. For instance, the spleen is located in most people in the upper left quadrant of the abdomen; are you going to make an adaptive case for why it’s on the left rather than the right? The actual reason almost certainly has nothing to do with adaptation or selection, and everything to do with historical and developmental mechanisms that are neutral with respect to selection.

M:. . . That behavioral features that have been selected for in our history are represented by modular components in the brain – again with rare exceptions, you can’t simply assign a behavioral role to a specific spot in the brain, just as you can’t assign a behavior to a gene.

P: No one in Ev Psych points to specific spots in the brain – that’s cognitive neuroscience, not evolutionary psychology. The only assumption is that there are functional circuits, in the same way that a program can be fragmented across your hard drive.

Now this is one of my peeves with evolutionary psychology. The evo psych literature is thick with papers emphasizing “modularity”; that evolutionary psychology FAQ I referenced before makes it clear that it’s an important concept in the field (and also ties it to concepts in computer science). Yet it is meaningless. Sometimes there’s the implication that the “module” is a discrete element in the brain, but it’s never clear whether they’re talking about a genetic module (an epistatic network of genes) or a neural module (an interconnected network of neurons), and when pressed, they retreat, as Pinker does here, to an admission that it could be just about anything scattered anywhere in the brain.

So my question is…why talk about “modules” at all, other than to reify an abstraction into something misleadingly concrete? Evolutionary psychologists don’t do neurobiology, and they don’t do genetic dissections, and they don’t do molecular genetics, so why do they insist on modularity? It’s premature and a violation of Occam’s razor to throw the term around, and also completely unnecessary — a behavior could be a product of diffuse general phenomena in the brain without diminishing its importance at all.

M: . . . That the human brain is adapted to a particular environment, specifically the African savannah, and that we can ignore as negligible any evolutionary events in the last 10,000 years, that we can ignore the complexity of an environment most of the evo psych people have never seriously studied, and that that environment can dictate one narrow range of outcomes rather than permit millions of different possibilities.

P: The savannah is a red herring – that’s just a convenient dichotomization of the relevant continuum, which is evolutionary history. A minimal commitment to “pre-modern” gives you the same conclusions. By saying that the brain could not have been biologically adapted to stable government, police, literacy, medicine, science, reliable statistics, prevalence of high-calorie food, etc., you don’t need to go back to the savannah; you just need to say that these were all relevantly recent in most people’s evolutionary history. The savannah is just a synechdoche.

Ah, a synechdoche. This is the evolutionary psychology version of the religious argument that it’s “just a metaphor.”

Again, this is a peeve I have with the field. I agree with the general principle that of course the brain is a product of our evolutionary history, and that there is almost certainly a foundation of genetically defined, general psychological properties of the mind…and that a great many specific psychological properties are not biologically adapted. Pinker is writing good common sense here.

But over and over, you see evolutionary psychologists falling into this trap of examining a behavior and then fitting it to some prior specific environment. They talk of a Savannah Mind or they generalize it to the Environment of Evolutionary Adaptedness. It’s another reification of the unknown. You don’t like “savannah”? Change it to “Pleistocene”. It’s just as broad and meaningless. It’s an attempt to reduce the complex and diverse to a too simple unit.

M: I’d also add that most evo psych studies assume a one-to-one mapping of hypothetical genes to behaviors. . .

P: 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.

By one-to-one, I mean the assumption that a behavior trait can be mapped to a contribution from a gene that was subject to selection for that trait; that it might be an additive property of a pleiotropic gene will be nominally noted, as Pinker does here, but operationally ignored. Remember, the issue is not whether genes contribute to our psychology, a point I totally agree with, but whether we can assign a selective origin to a behavior. That is a much, much harder problem.

M [continuation of previous sentence]:. . . and never actually look at genes and for that matter, ignore most human diversity to focus on a naive typological simplicity that allows them to use undergraduate psych majors at Western universities as proxies for all of humanity”

P: It’s psychologists, not evolutionary psychologists, who focus on Western undergrads –field research and citations of anthropology are vastly more common in ev psych than in non-ev-psych. PZ is engaging in prosecution here, not analysis – he’s clearly ignorant of the sociology of the fields.

As for diversity – is he arguing for genetic differences among human groups, a la Herrnstein & Murray?

First, this has already been addressed by Stephanie Zvan: when you look in the evolutionary psychology journals at papers identified as evolutionary psychology, you find…a focus on Western undergrads. I throw up my hands in exasperation. Look at the actual work done in your field, not the abstract ideal you hold in your head. I get my vision of evolutionary psychology by reading the papers.

Secondly, what a weirdly off-target attempt at ad hominem. Once again, my criticisms are being addressed by imagining motives; in Jerry Coyne’s critique, I’m an uber-liberal offended at the consequences a genetic component to behavior might have on my egalitarian biases; now Pinker takes a swipe by tarring me with the likes of Herrnstein & Murray. Make up your minds!

For the record, of course there are genetic differences in human populations! It’s an open question whether any of them make significant contributions to human psychology, however. I’m open to evidence either way.

But my remark was about cultural diversity (which also, by the way, exists). Setting aside the notion of a genetic component for now, we know that culture creates different minds. How can you analyze the causes of a behavior if your work focuses on a relatively uniform sample?

M: Developmental plasticity vitiates most of the claims of evo psych. Without denying that some behaviors certainly have a strong biological basis, the differences in human behaviors are more likely to be a product of plasticity than of genetic differences. . .

P: 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. For example if you silence *all* synaptic activity in the brain of a developing mouse with knock-outs, the brain is pretty much normal.

Speaking of straw men…I found The Blank Slate entirely unreadable, unlike most of Pinker’s books, because of the gigantic straw man erected in the title. This flailing against me is a product of this weird idea that I reject the contribution of our genes to our minds, but just as there are no evolutionary psychologists who believe everything in our brains is genetically predetermined, there is no such thing in serious science as a “blank slater”.

There is a continuum, and we’re arguing about degrees. For example, take a child of French parents and raise them in the United States, they’ll grow up speaking fluent English (or Spanish, depending on the household), and vice versa — an American child raised in France will speak French like a native. There is no genetic component to the details of language. Yet when you compare diverse languages you can start to pick out commonalities, and when you look at the neural substrates of language you do see shared anatomy and physiology — I do not hesitate to accept that there is an evolved component of human language. The differences between speakers are learned, the universals may well be biological.

Which means that when evolutionary psychologists try to parse out variations between different groups, racial or sexual, I suspect it’s most likely that they are seeing cultural variations, so trying to peg them to an adaptive explanation is an exercise in futility. When evolutionary psychologists try to drill down and identify the shared components, I’m much more willing to see their efforts as interesting.

That last sentence by Pinker is a lovely example of nonsensical denial of the importance of plasticity. “Pretty much normal” means that on broad, superficial inspection the various components of the brain are present — hindbrain, midbrain, forebrain, various nuclei and pathways, they’re all there. I’ve seen the same thing in zebrafish: the peripheral motor nerves I studied as a graduate student form perfectly normally even if you knock out all the acetylcholine receptors, so that the muscles are totally unresponsive to physiological inputs.

This does not surprise me. Most of the patterning of the brain is set up in the embryo before neuronal connectivity is established; the clock-like activity of mitotic rate genes defines the size of various bits of the brain; adhesive and repulsive cell surface interactions lay out the major pathways. Does Pinker think someone trained in developmental neurobiology would expect that the brain would collapse into a formless blob in the absence of action potentials and synaptic transmission?

But it is still absurd to call the deprived brain “pretty much normal”. When you look deeper, you find subtle and important differences. The clearest examples are found in experiments with visually deprived cats: sew one eyelid shut, or both, or alternate, in a young kitten, and you can find all kinds of changes in visual processing, detectable at both the physiological and anatomical levels. The visual cortex forms, projections from the lateral geniculate terminate in roughly the right place, but they absolutely depend on visual input to fine tune their connections. Human children born with visual deficits in one eye will also have lifelong deficits in visual processing, even if the original problem is corrected.

Try raising a child without contact with other humans. I guarantee you that their brains, when physically examined, would look “pretty much normal”…but does anyone really believe that psychologically, on the level evolutionary psychologists study brains, that they’d be “pretty much normal”?

This is “pretty much normal” behavior from evolutionary psychologists, though. Point out that that their inferences about neuronal circuitry are bogus, they tell you that they don’t study neurons anyway; tell them that the behaviors they study are awfully plastic and flexible, and presto, hey, look, brains and neurons are patterned by genetic elements. The sleight of hand is impressive, except when you realize that science shouldn’t be about magic tricks.