PZ Myers was recently part of a panel on Evolutionary Psychology (EP) at the science fiction and fantasy convention CONvergence. A number of people involved in EP have criticised PZ's account of EP, (see the articles here, here and here, as well as earlier posts on this blog as examples) Jerry Coyne and Steven Pinker amongst them.
PZ has answered Coyne and Pinker and I find his answers continue to mislead people about what Evolutionary Psychologists actually suggest and study. I am not particularly interested in his post answering Jerry Coyne, save to say it says nothing pertinent about the field. In short PZ accuses Coyne of a "dignified retreat" (by which I take him to mean people talking more carefully and conservatively to hostile audiences than friendly ones - I will get to this later, save to say I feel PZ is guilty of the same and that he strangely identifies Coyne as providing "a perfect example" of the sort of dignified retreat he feels evolutionary psychologists perform, this being odd as Jerry is not an evolutionary psychologist), bemoans Coyne's occasional descent into ad hominem (I hear that if you live by the sword you die by the sword) and generally says nothing about EP beyond the same strawman stuff he said in the talk.
However his post Tackling Pinker's defense of Evolutionary Psychology is more interesting, though no less misleading.
A note on colour coding. Green text is stuff from the Coyne/Pinker defence or other EP sympathisers, orange text PZ and grey text is me (I'm aware of the semiotic implications of assigning green to allies and orange to opponents - forgive me).
If you can't be bothered to read on the short version is: I disagree with pretty much everything PZ says, I think it's clear he hasn't much of an idea how psychology works, let alone how EP works. I concede that Steven Pinker gave too glib a response to qualms about studies being performed mainly on college students, but that to concentrate on this this misses a bigger picture that I hope to illustrate.
Another short note: If anyone wants to bring this to PZ's attention feel free, but I won't be bothering myself because it's clear to me that he isn't listening. This is for my own education and anyone else who might be genuinely interested.
After some contextual preamble PZ begins:
I dislike evolutionary psychology.
Now this is mostly an irrelevance, but isn't this a "dignified retreat"? Seems to me PZ is much happier to use harsher language in safer territory. For example according to this transcript of the CONvergence talk his words were...
My bias is, I despise [EP].
...and the rest of his input in that arena seemed consistent with that tone.
Now whilst I think this is a clear example of the sort of "dignified retreat" PZ condemns in others I don't mention it merely to highlight his hypocrisy, but to bring up something that will be a recurring theme: yes, we do talk more confidently in front of friends than we do critics, and sometimes there are perfectly good reasons to do so. This will become important later on.
PZ moves on to quote Pinker responding to him:
Myers: 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). . .
Pinker: 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.”
To which PZ says:
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.
I have two important objections to this.
The first and most important objection: They. Don't. Do. This. To adopt Pinker's rhetoric, "every" and "poorly" are the straw-man giveaways here, as well as the implication that evolutionary scenarios are necessarily constructed prior to tests.
Evolutionary psychologists are perfectly aware that sociocultural factors, individual differences and neurological quirks are responsible for all sorts of human behaviour. They therefore focus, quite painstakingly in the main, on what can be shown to be cross-cultural propensities in human behaviour.
Now there's a second point, which may seem at odds with the first but which actually need not be.
It is arguably the main priority of evolutionary psychologists to account for what other perspectives in psychology have trouble explaining. It isn't so much that EP typically shoehorns evolutionary explanations onto psychological issues we already have concrete sociocultural/individual explanations for, it is when a sociocultural/individual explanation for behaviour falls short that a phenomena for which an evolutionary line of enquiry might be rewarding is indicated.
So the impression PZ seems keen to give is that evolutionary psychologists chose any old behaviour (arbitrarily), ignore conflicting accounts and make up some kind of shoddy demonstration of a phenomena they have decided upon from the outset.
Whilst I cannot deny the existence of inept and/or corrupt practitioners (can any field?) I feel a fairer summary is that they are well aware of phenomena for which there are solid explanations and concentrate on those which seem to be propensities throughout the species (and sometimes throughout other species too) and test them to standards in-line with those of social science generally.
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.
Would I make an adaptive case for why the human spleen tends to be on the left rather than the right? No, but I think a strong adaptive case can be made for why it's in the abdomen rather than the head. Now I know little about the spleen aside from it's size and main functions, but I doubt it's either arbitrary or elaborate to suggest that the reason it's in the abdomen is because there are fewer costs to the organism it being there than elsewhere.
So whilst it's naïve to assume certain things about it's position, it doesn't seem naïve to assume other things about it's position. Does it matter if it's on the left or right? I doubt it. Does it matter that it's not on the end of my nose? I think so.
Given that they are talking in general terms I don't suppose there's much more to be said about the spleen analogy. However, Pinker's point was not that there wasn't something about the spleen that might be down to chance, but that there were apparent functions about which we can make assumptions that are based in sound reasoning.
Including some things about its position.
So I think PZ misses the point here. Perhaps he can hold up individual studies that really do make arbitrary judgements and construct elaborate scenarios to justify them (again, show me a field without dodgy practitioners). Pinker's point is that representative studies put in a lot more thought and discipline than PZ gives credit to.
PZ moves on to Pinker's next defence:
Myers:. . . 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.
Pinker: 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.
To which PZ responds:
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.
Interesting to note that he is aware of the FAQ. I will bring this up again later on.
Anyway - No it's not meaningless, it's confusing maybe, but not meaningless.
What seems to often get lost in these discussions is that psychologists study behaviour first and foremost. Given that evolutionary psychologists are overwhelmingly materialists (in the philosophical sense) it stands to reason that the root cause of behaviour resides in the brain/nervous system in the form of electrochemical stimulus acting on physical bits of the brain and body.
So can you show someone a phenomena like a memory or a heuristic in the brain? Well I don't know, but as a materialist I would say that at some level you could, that "this nerve doing this as these synapses do that and reaching these areas equals a certain feeling or thought" isn't a naïve notion. However, it isn't how psychologists demonstrate things like memories or heuristics, they do so via experimentation, brain imaging, studying the effects of brain injury and disorder, and so on.
I think this sort of thing (ability to recall a memory, effect of a heuristic) is what Pinker means by a functional circuit.
Now many such circuits are built largely as a result of environmental inputs, but not all are. They certainly all rely on innate structures.
If that is accepted then what is there to say that it is naïve to assume that certain propensities to behaviour are innate to neurotypical human minds? All such things must be partially, mostly or wholly innate.
Evolutionary psychologists tend to call those processes that they are confident to be largely or wholly innate mental modules.
PZ says he is unclear whether this means a genetic module or a neural module.
Neither. It's an innate behavioural process. There is presumably a neural network that lies behind the process (and depending on the behaviour in question there is more or less evidence to demonstrate such a thing). Given that it is innate there must be a genetic basis to the neural network which supports the process (and certain neurology with heritable components provide evidence of this, like autism and theory of mind).
So in order to resolve the confusion there are three levels of understanding:
1) They are looking at a bit of behaviour (a psychological process for which there is a demonstrable propensity in humans).
2) It stands to materialist reason that part(s) of the brain are involved - a neural network.
3) Because it's thought to be innate it stands to reason that genetic factors influence (if not outright dictate) the building of the network.
Is Pinker engaged in a retreat? As far as I can see it his attitude has been consistent for last 16 years or so judging from "How the Mind Works" in which he talks of modules in much the same way he does here. For example:
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 - How the Mind Works page 30.
The only thing Pinker "retreats" from is the position PZ assumes evolutionary psychologists adopt - a position Pinker (and most evolutionary psychologists) never held.
So my question is…why talk about “modules” at all, other than to reify an abstraction into something misleadingly concrete?
It's the jargon the practitioners have decided upon for phenomena they deem less abstract than PZ does (I also recommend the response given to this query here).
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?
Asides from the reasons already stated - some evolutionary psychologists do do such things, or work alongside those who do.
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.
Is it necessarily a violation of Occam's razor to assume that "important" propensities in behaviour have not resulted from selective processes in part or in whole? Seems counter-intuitive to me.
As for "a behaviour could be a product of diffuse general phenomena..." yes, it could, and the concept of modules covers that if it is properly understood.
Back to Pinker's defence:
Myers: . . . 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.
Pinker: 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.
To which PZ says:
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.
Yes, it's a reification of the "unknown" (some of the phenomena in question are better understood than others, of course) ... based on the available evidence and undertaken according to the standards of social science. There are better ways of thinking about it than "Savannah Mind" in my opinion ("Pleistocene Mind" would be better), but better still is the understanding that notable change in the Holocene is tentatively ruled out. However, silly as these notions might seem on face value they are based on paucity of evidence to the contrary. If you want to overturn them show us the innate behavioural propensity that has arisen in the interim or show us the innate psychological distinctions between populations that haven't had much contact during the Holocene.
Can't do it? Neither can I.
That's why I accept that in terms of our innate behavioural propensities the Holocene is of no particular consequence. Do some such propensities speak to life in Africa? Yes, and they need examining and criticising individually and on their own terms.
To further the point - my understanding is that Australian aborigines were effectively genetically isolated throughout the Holocene until the arrival of Captain Cook, so what innate psychological differences to other humans do they display? "None" is the received wisdom here, hence the contention.
So pointing out that "Savannah Brain" is a metaphor is not like a religious "just a metaphor" argument. It's more like pointing out that "survival of the fittest" as a shorthand for the process of natural selection is figurative to a degree. It's a useful summary for those who know what they mean and where the limits are, but can be misleading if taken too literally.
Pinker's point then is not that evolutionary psychologists do not use the term and pursue related lines of enquiry, but that PZ once again attacks a strawman with arguments like "...the human brain is adapted to a certain environment, specifically the African savannah...". No, certain behavioural propensities seem suited to an ancestral African environment, even among those who have never lived in such a place, but not all.
Myers: I’d also add that most evo psych studies assume a one-to-one mapping of hypothetical genes to behaviors. . .
Pinker: 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.
Ah! This looks to me like a dignified retreat.
People look to PZ as an educator - his students (who he advises not to show interest in EP), those who read his blog, those who attend his speaking engagements. When he means "they reckon certain behaviours are innate and therefore influenced by our genes" perhaps he should say "they reckon certain behaviours are innate and therefore influenced by our genes". Because that's a more modest claim than "they assume one-to-one mapping of genes to behaviours", which is nonsense.
By the way, whoever said these problems weren't hard?
The next part of Pinker's defence.
Myers [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”
Pinker: 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.
To which PZ responds:
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.
I have some sympathy for PZ here but I think he missed the point (again). Pinker could have made it clear that the vast majority of studies into psychology begin with experiments in universities on participants who are overwhelmingly students (of psychology, no less).
But in coming to an understanding of any given phenomena this is usually acknowledged by those in the field as a tentative first step. Most studies in psychology won't be taken seriously until they have been replicated, replicated with different sorts of participants, contrasted to similar experiments with different independent variables and so on.
And with this taken on board Pinker is right, studies in EP do tend to make greater use of field work and anthropological studies, even cross-species studies, in relation to psychology in general.
Does a focus on western undergrads remain? By necessity yes (I urge those reading Stephanie's post to check out ChasCPeterson's comments, in fact I recommend his comments on this subject in general). However conclusions from such studies will tend to be tentative until further studies are performed showing that the behavioural patterns hold true across cultures (and sometimes even species).
Generally when it comes to social science I find the notion that you can get a good perspective from reading papers to be erroneous. No one study or experiment can account for all the variables to produce a solid conclusion. Critics such as PZ and Stephanie are almost always going to be able to rip apart a single study provided they ignore the body or work that it's in dialogue with. It is meta-analyses and text books that give you a firm grounding in the subject, from there you can properly appreciate the strengths and weaknesses of any given study. It is also poorly understood that those writing psychological studies are encouraged to make tentative conclusions and then follow up with a speculative analysis. This does seem to be something that causes confusion.
As Pinker says PZ seems ignorant of the sociology of the fields, and I think this is clear from his conflation of EP (if not psychology) with neuroscience.
It's also worth taking some time to read this defence of the pertinence of WEIRD studies by Ed Clint.
Pinker (I think, or it may be Coyne) also states:
As for diversity – is he arguing for genetic differences among human groups, a la Herrnstein & Murray?
To which PZ says:
Secondly, what a weirdly off-target attempt at ad hominem.
This is tangential, but I don't think it was ad hominem. It was a question that resulted from the statement "...they ignore most human diversity..." and seeing as we are talking about psychology the response was therefore pertinent (it certainly popped into my head as I hope previous blog posts demonstrate). Where is there diversity in innate psychological propensity or capacity between human populations?
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!
Why is Pinker assumed to duplicate Coyne's apparent opinion on the matter? They are different people are they not? Presumably PZ is ignorant of Pinker's defence of Herrnstein in "The Blank Slate" (though I will point out he hasn't offered a similar defence of Murray).
Anyway, PZ does sort of answer the question:
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.
Which makes it all the more confusing as to why PZ moaned about evolutionary psychologists ignoring human diversity. They (as a gestalt) have looked hard for evidence of differences in innate psychological propensities in different human populations. They have yet to find any. Therefore the contention is that there isn't any pending further developments.
I mean, this is discussed prominently in the same EP FAQ PZ claimed to have read earlier.
But my remark was about cultural diversity (which also, by the way, exists).
I'm going to try and avoid hyperbole here, but I reckon if I had a tenner for every time I've seen Steven Pinker acknowledge the existence of sociocultural influence I could buy a brand new American Standard Telecaster.
Last time I looked they were about £500.
I think it's important to note here that not all sociocultural differences rule out evolutionary explanations for behaviour. Some of them even indicate it. For example Inuit people living near the north pole wear more clothing than equatorial bushmen. This is a sociocultural phenomenon. However the behaviour is clearly informed by the fact that humans don't like to feel too hot or too cold, to which our natural history is pertinent.
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?
Easy - by making only the most tentative of judgements about said behaviour until similar studies on different sets and types of participants are conducted.
Anyway, last bit:
Myers: 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. . .
Pinker: 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”.
Elsewhere PZ claims to have read the book. Seems odd not to read it because of the title. Personally I think it's the most readable of Pinker's books. I've never had problems with parsing a book because of the title. Just me?
This seems to be another dignified retreat. Remember the things PZ said that provoked this defence:
Plasticity is everything.
How does that differ from notions of a blank slate?
But it's by the by. The Blank Slate wasn't written about PZ. To be frank this seems like projection. Perhaps PZ sees himself as something of an heir to Gould, who Pinker is critical of from time to time. This isn't mere conjecture on my part - if you contrast PZs complaints in the CONvergence talk with those Gould gave EP they deal with the same sort of subjects (for example PZ and Gould both think the existence of writing poses a problem for the sort of modularity proposed by EP - it does not).
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.
Yeah fair enough, I mean the only thing missing from this bit is an acknowledgement that this is exactly the sort of thing evolutionary psychologists acknowledge.
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.
Once again the assumption is made that it is somehow representative of EP to stress psychological differences between races. Talking gestalt - the exact opposite is true. If we moderns are psychologically equivalent to people of 12,000 years ago it stands to reason that we are psychologically equivalent to each other. In fact it is the confidence that we are psychologically equivalent to each other that leads to the notion that we are psychologically equivalent to those of the late Pleistocene.
Sex differences seem to be the elephant in the room, as evolutionary psychologists do propose a number of them. They are usually careful to discuss those that are demonstrated cross culturally (and sometimes cross-species).
Whilst I imagine no amount of reassurance in regard to the examination of sex differences will convince all critics that EP isn't somehow opposed to women's liberation I will trot out what I see as the party line on the matter. Such differences are small and statistical. They are matters of overlapping distribution. Nothing in EP rules out the notion that an individual of either sex might be well suited (or even optimal) in a job or social role typically associated with the opposite sex. A man might be a better communicator than most women despite noted trends to the contrary, a woman might be more inclined to bloody violence than most men despite noted trends to the contrary, and so on.
After this PZ engages Pinker over his anecdote about the mouse. I won't quote it all because it's lengthy and based around another apparent misconstruction of Pinker's point. I feel that it is summed up with the paragraph:
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”?
But if it were a typical baby would it still display certain propensities? Avoid the edges of cliffs? Display certain emotions? Cry when scared? Feel hunger? Abhor the smell of excrement? Develop a theory of mind between the ages of 3 and 5? Respond to a smile? And so on...
Pinker's anecdote was to show that environmental input has negligible impact on the structure of the brain (I anticipate objections such as presence of poisons or denial of nutrition, so these things aside). Therefore we know that genes order the brain. The argument regards what content they supply it with.
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.
Asking critics to understand the nuances behind the jargon they criticise is not an attempt at chicanery.