Richard Dawkins
At the end of such a compendium—truly a worthy 23-years-on successor to The Adapted Mind (Barkow, Cosmides, & Tooby, 1992) and 10-year successor to the first Handbook of Evolutionary Psychology (Buss, 2005)—what is there left for an afterword to say? An attempted summing up of all 52 chapters? Too repetitious. A prophetic “Whither Evolutionary Psychology?” Too presumptuous. An idiosyncratic jeu d'esprit, playfully calculated to send the reader diving back into the book to view the whole corpus again but from a different angle of illumination? Rather daunting, but I'll give it a go. Reflective musings of a sympathetic observer of the scene? Well, let me try that too and see what develops.
First, a confession. As a sympathetic observer of the scene, I had not been a very clear-sighted one. I was one of those who mistakenly thought “evolutionary psychology” a euphemistic mutation of “sociobiology,” favored (like “behavioral ecology”) for its cryptic protection against the yapping ankle-biters from “Science for the People” and their later fellow travelers. I now think that was a travesty, not even a half truth, perhaps at most a quarter truth. For one thing, intellectual heroes of the caliber of Cosmides, Tooby, and other authors of this book need no camouflage. But even that isn't the point. The point is that evolutionary psychology really is different. Psychology it is, and psychology is by no means all, or even mostly, about social life, sex, aggression, or parental relationships. Evolutionary psychology is about the evolution of so much more than that: about perceptual biases, about language, about revealing errors in information processing. Even within the narrower field of social behavior, evolutionary psychology distinguishes itself by emphasizing the psychological and information-processing mediation between natural selection and the behavior itself.
Evolutionary psychology and sociobiology do, however, have one bane in common. Both are subject to a level of implacable hostility that seems far out of proportion to anything sober reason or even common politeness might sanction. E. O. Wilson, struggling to understand the onslaught that engulfed Sociobiology at the hands of left-wing ideologues, invoked what Hans Küng in another context had called “the fury of the theologians” (Wilson, 2000). I have known sweetly reasonable philosophers, with whom I could have an amicable and constructive conversation on literally any other topic, descend to the level of intemperate ranting at the mere mention of evolutionary psychology or even the name of one of its leading practitioners. I have no desire to explore this odd phenomenon in detail. It is well discussed by evolutionary psychologists including contributors to this book, and also by Ullica Segerstråle in Defenders of the Truth (2000). I do have one additional remark to make about this negativity, and I shall return to it. First, though, in what I intended to be a more positive vein, here is the nearest approach I can make to the jeu d'esprit that aspires to shed a little oblique light on the material in this book, from an unfamiliar angle.
Sometimes science proceeds not by experiment or observation but by changing the point of view: seeing familiar facts from an unfamiliar point of view. Two candidates for this role are “The Genetic Book of the Dead,” and “Continuously Updated Virtual Reality.” I shall briefly summarize them, and then try to bring them together in a way that I hope might provide the oblique light that I rashly promised (for fuller accounts of them, see Chapters 10 and 11, respectively, of Dawkins, 1999, and also my forthcoming autobiography, 2015, Brief Candle in the Dark).
The idea of the Genetic Book of the Dead is that an animal, since it is well adapted to its environment, can actually be seen as a description of its environment. A knowledgeable and perceptive zoologist, allowed to examine and dissect a specimen of an unknown species, should be able to reconstruct its way of life and habitat. To be strict, the reconstruction is a complicated average of the ancestral habitats and ways of life of the animal's ancestors: its EEA, to use the evolutionary psychology jargon.
This conceit can be phrased in genetic terms. The animal you are looking at has been constructed by a sampling from the gene pool of the species: genes that have successfully come down through a long sequence of generational filters—the filters of natural selection. These are the genes that had what it takes to survive in the EEA. They fit the EEA as a key fits a lock, and, like a key, they are a kind of negative impression of their lock. Genes can therefore be seen as a description of the EEA, written in the language of DNA: hence the phrase Genetic Book of the Dead.
Continuously Updated Virtual Reality is the idea that every brain constructs a virtual reality model of the world through which the animal is moving. The virtual reality software is continuously updated in the sense that, although it might theoretically be capable of simulating scenes of wildest fantasy (as in dreams), it is in practice constrained by data flowing in from the sense organs. What the animal perceives is a virtual reality rendering of objects in the real world.
Visual illusions such as Necker cubes and other alternating figures are best interpreted in these terms. The data sent to the brain by the retina are equally compatible with two virtual models of a cube. Having no basis to choose, the brain alternates.
The virtual world that our brains construct is, no doubt, very different from that of a squirrel, a mole, or a whale. Each species will construct virtual models that are useful for its particular way of life. A swift and a bat both move at high speed through three dimensions, catching insects on the wing. Both therefore need the same kind of virtual model, even though swifts hunt by day using their eyes, and bats hunt by night using their ears. Qualia that swifts associate with color are actually constructions by the virtual reality software. My conjecture could probably never be tested, but I think bats might “hear in color.” Their virtual reality software is likely to make use of the same qualia as swifts use for light of different wavelengths, but to signify equally salient features of a bat's auditory world. Surface textures are likely to be as important to bats as color is to swifts, and textures like the hairy pelt of a moth, the sheen of a bluebottle, or the rough stone of a cliff presumably temper echoes in particular ways. So the virtual reality software of bats is, I suggest, likely to adopt the same qualia—red, blue, green, and so on—as internal labels for different acoustic textures. Redness and blueness are constructions of the brain's virtual reality software, and natural selection will have seen to it that such qualia are used as labels for things that really matter to the survival of the respective animals: color for a visual animal like a swift or a person; texture for a bat.
My bat suggestion is just an example of how the idea of Continuously Updated Virtual Reality changes our view of animal psychology. Now I want to unite it with the idea of the Genetic Book of the Dead. If a knowledgeable zoologist can reconstruct a species' EEA using data from its anatomy and physiology, could a knowledgeable psychologist do something similar for mental worlds? Surely the mental world of a squirrel would, if we could peer into it, be a world of forests, a three-dimensional maze of trunks and twigs, branches and leaves. The mental world of a mole is dark, damp and filled with smells, because the genes that built its brain have survived through a long line of similarly dark and damp ancestral places. The virtual reality software of each species would, if we could reverse engineer it, allow us to reconstruct the environments in which natural selection built up that software. By the same reasoning as before, it is tantamount to a description of the EEA.
Nowadays we are accustomed to saying, in a sense that is more literal than metaphorical, that all the genes of a species have survived through a long succession of ancestral worlds, including both physical and social worlds. My suggestion here is that the long succession of ancestral worlds in which our genes have survived include the virtual worlds constructed by our ancestors' brains. Real genes have—again, in something close to a literal sense—been selected to survive in a virtual EEA, constructed by ancestral brains.
That's enough of that. I said I'd return to the hostile reception that evolutionary psychology has received in certain circles. It is a methodological point I am making, and the note I want to strike is one of encouragement.
Skeptical investigators of paranormal claims have a much quoted maxim: Extraordinary claims require extraordinary evidence. All of us would set the bar very high for, say, a claimed demonstration that two men, sealed in separate soundproof rooms, can reliably transmit information to one another telepathically. We should demand multiple replications under ultrarigorous double-blind controlled conditions, with a battery of professional illusionists as skeptical scrutineers, and with a statistical p-value less than one in a billion. On the other hand, an experimental demonstration that, say, alcohol slows down reflexes would be accepted without a second glance.
While nobody would approve poor design or shoddy statistics, we wouldn't go out of our way to scrutinize the alcohol experiment very skeptically before accepting the conclusion. The hurdle in this case would be set so low as almost to escape notice. In the middle, there is a spectrum of scientific claims, of intermediate capacity to arouse a priori skepticism. Evolutionary psychology, weirdly, seems to be seen by its critics as way out on the “telepathy” end of the spectrum, a red rag to critical bulls.
Something similar was true of the earlier controversy over sociobiology. Philip Kitcher's Vaulting Ambition (1985) is widely touted as a devastating critique of human sociobiology. In reality, it is mostly a catalog of methodological shortcomings of particular studies. The supposed faults range from peccadillo to shoddy, but they are of a type that is in principle remediable by new and improved studies along the same lines. Criticisms like Kitcher's of sociobiology, or like those more recently hurled at evolutionary psychologists such as Daly and Wilson on stepparental abuse, Cosmides and Tooby on social exchange, or Buss on sexual jealousy, are made so strongly only because the critics are treating the hypotheses under test as if they were extraordinary claims that demand extraordinary evidence. Evolutionary psychology is seen by its critics as out at the high hurdle end—the “telepathy” end of the spectrum—while it is simultaneously seen by its practitioners as down at the plausible end of the spectrum with the alcohol and the reflexes. Who is right?
Without a doubt, the evolutionary psychologists are right in this case. The central claim they are making is not an extraordinary one. It amounts to the exceedingly modest claim that minds are on the same footing as bodies, where Darwinian natural selection is concerned. Given that feet, livers, ears, wings, shells, eyes, crests, ligaments, antennae, hearts, and feathers are shaped by natural selection as tools for the survival and reproduction of their possessors in the particular ecological niche of the species, why on earth should the same not be true of brains, minds, and psychologies? Put it like that, and the central thesis of evolutionary psychology moves right along to the plausible end of the spectrum. The alternative is that psychology is uniquely exempt from the Darwinian imperatives that govern the whole of the rest of life. That is the extraordinary claim which, if not downright bonkers, at least demands extraordinary evidence before we should take it seriously. Maybe it is right. But given that we are all Darwinians now, the onus of proof is on those who would deny the central thesis of evolutionary psychology. It is the critics who lie closer to the “telepathy” end of the spectrum.
Could it be that the sticking point for critics is that old bugbear, the supposed uniqueness of humans? Is evolutionary psychology permissible for “animals,” but not Homo sapiens? Once again, such exceptionalism, which Darwin himself fought and popes still hanker after, although conceivably justifiable, bears the heavy burden of proof. There are perhaps 10 million species alive on this planet at the moment, and as many as a billion species have done so in history. It is, of course, possible that our species really is the one in a billion species that, with respect to psychology, has emancipated itself from the purview of evolutionary explanation. But if that is what you think, the onus of demonstration is on you. Don't underestimate the magnitude of the surprisingness of that which you purport to believe.
Or could it be “modularity” that sticks in the craw of critics? Maybe. Maybe they are right, and in any case, some evolutionary psychologists are less enamored of modularity than others. But, yet again, modularity is not an extraordinary claim. It is the alternative to modularity that bears the burden of coming up with extraordinary evidence in its favor. Modularity is a universally good design principle that pervades engineering, software, and biology, to say nothing of political, military, and social institutions. Division of labor among specialist units (experts, organs, parts, subroutines, cells) is such an obvious way to run any complex operation, we should positively expect that the mind would be modularized unless there is good reason to believe the contrary. Yet again, the detailed arguments are to be found in this book. I merely repeat my point about the onus of proof lying on the opponents of evolutionary psychology.
Of course, some individual evolutionary psychologists need to clean up their methodological act. Maybe many do. But that is true of scientists in all fields. Evolutionary psychologists should not be weighed down by abnormal loads of skepticism and a priori hostility. On the contrary, they should hold their heads high and go to work with confidence, for the enterprise they are engaged upon is flourishing normal science within the neo-Darwinian paradigm. This book shows the way.