Luke Maurits

I recently finished reading Robin Dunbar’s “Grooming, Gossip and the Evolution of Language”, a fairly short and quite readable book which advances the hypothesis that the human language faculty evolved initially for the purpose of “social grooming”, i.e. strengthening social bonds between individuals in larger social groups, and then later was co-opted for the purpose of “gossiping”, i.e. talking to each other about each other.  More generally the book is concerned with the connection between cognition and social behaviour (and contains discussion of the well known “Dunbar’s number“).

The ideas in the book are well argued and I find myself without any good reason to reject most of them, although the possibility exists that there are better argued alternatives I’m not aware of.  My biggest complaint is that Dunbar’s rhetoric seems to blur the distinction between what language fundamentally does and how we preferentially use language.  I don’t have exact quotes, but there are several places in the book where Dunbar says things to the effect of “language evolved not for the purpose of exchanging information about the world around us, as we so often assume, but for exchanging information about each other for social purposes”.  This phrasing baffles me somewhat, because other human beings are part of the world around us.  Language is, by Dunbar’s hypothesis, for exchanging information about the world around us, it just happens that kind of information about the world around us which we preferentially exchange – and possibly the only kind that our ancestors exchanged – is each other.

This might seem like an odd or insignificant complaint to make, but my motivation for reading Dunbar’s book (and for reading more in general about the evolutionary origins of language) was considering the applicability of Andersonian rational analysis to language.  My recent research has centred around the Uniform Information Density (UID) hypothesis, which is theoretically motivated by the idea that human language is a roughly optimal solution to the problem of high-speed, high-reliability exchange of information (rational analysis in general holds that human cognitive faculties represent roughly optimal solutions to specific problems).  I have heard people question the applicability of this view to language, and in particular suggest that language is not essentially “for” information exchange but rather for various social interactions.  It seems implicit in this line of argument, and in much of Dunbar’s rhetoric, that these are orthogonal or mutually exclusive goals, but after reading this book I think that in fact one is simply a special case of the other, which is good news for rational theories of language.

This reassurance aside, I think the other thing I got most of reading Dunbar’s book was an appreciation for the continuity between the behavioural (and so presumably cognitive) traits of primates, including humans.  Cognitive science seems to be a fairly anthropocentric field – for obvious reasons – but it seems to me like it would often make a lot of sense to take a more inclusive view.  Perhaps attempts at modelling individual differences should also try as best they can to model inter-species differences at cognitive tasks which non-human primates are unanimously considered capable of?

The idea of applying an evolutionary perspective to the study of psychology has been hugely controversial, and I’ve never fully understood why.  Dualistic theory of mind has been effectively dead for a very long time.  Just about everybody who thinks about these things today is of the opinion that the structure and function of the mind is a reflection of the structure and function of the brain.  The brain is made of cells, and so when it comes to scientific explanations of its structure and function, evolution is the only game in town.  Any complete account of the human mind and how it came to be must necessarily include an evolutionary component.

These are all of the objections to integrating evolutionary thinking into psychology that I have either seen or can anticipate, and why none of them hold water:

• “Evolutionary psychology is bad because it will (or might) end up providing a scientific justification for racism, sexism, or some other unpleasant -ism”.  This is a straight up example of the well known is-ought fallacy.  It’s absolutely not a valid argument against EP or anything else.
• “Evolutionary psychology is a junk science full of speculative “just so” stories without any hard evidence”.  This may well be a valid criticism against some, or even many, of the particular ideas which have been developed under the guise of evolutionary psychology, but it’s not a good reason to discard the entire field.  The appropriate response to bad science which combines evolution and psychology is good science which combines evolution and psychology, not a declaration that evolution and psychology shall never meet.   Such a declaration can only be justified by an argument that good evolutionary psychology is impossible in principle.  As far as I know, no convincing argument of this kind has been made, and it seems unlikely to me that one ever will.
• “But, but, but, what about culture?”.  Bringing evolutionary thinking into psychology does not eliminate the possibility of cultural explanations for some phenomena, and in turn the explanatory power of culture does not completely eliminate the need for evolutionary thinking.  Culture isn’t magic: any given cultural influence on thought necessarily has to (i) be an influences on something, and that something has to have existed prior to the particular cultural influence under consideration, and (ii) have bene acquired by some mechanism, which again has to have existed prior to this particular cultural influence.  Evolution is the only thing which can terminate the infinite regress which results from trying to use culture as an explanation for everything.  Biological evolution and cultural evolution are complementary processes, and not at odds with one another.
• “Not everything in an organism’s phenotype represents an adaptation to some function.  The evolutionary process can also lead to traits which are exaptations, or spandrels”.  This is a prefectly valid claim in and of itself (although it’s not necessarily true – I haven’t done enough reading on the “Darwin Wars” to definitively come down on the side of Dawkins or Gould, although I’d love to have done so and fully intend to do so), but it doesn’t really remove the role for evolution in psychology.  It discredits one particular conception of evolutionary psychology, i.e. the conception in which everything is an adaptation.  But all this does is force us to widen our conception of what evolutionary psychology is, from “explaining as much of psychology as possible in terms of adaptations” to “explaining as much of psychology as possible in terms of adaptations, exaptations or spandrels”.
• “The mind is emergent magic!  Chaos, fractals, self-organisation!”.  My characterisation of this school of thought is tongue-in-cheek, but it does represent a perfectly legitimate take on the human mind.  However, once again, it’s not a magic ticket away from evolution.  The full complexity of the human mind may well emerge in some seemingly magical way from the simple, local interactions of individual neurons in the human brain, but that same complexity does not emerge from extremely similar simple, local interactions of individual neurons in the brains of cats and dogs.  Clearly there is some set of preconditions for the emergence of various psychological traits, and if we establish what those preconditions are we will be faced with the task of explaining how evolution drove our brains to meet those preconditions from a previous state which did not.  Evolution cannot have proceeded with foresight toward those preconditions because of the benefits that would emerge from them: each step along the way must have yielded its own benefits, and the story isn’t complete until we know what those steps were and why they happened.

No matter what your particular beliefs are about how the mind or evolution works (well, assuming they’re not dualist in the case of the mind), there’s just no way you can completely separate the two.  “Evolutionary psychology” isn’t some distinct subfield which you can ignore or choose not believe in.  All of psychology is under the influence of evolution, and it is a totally legitimate goal of the science to eventually account for all of these influences.  It’s conceivable that we can completely ignore this part of psychology until “the end”, characterising the functionality of all the various psychological traits without any recourse to evolutionary thinking at all and then tying it all together with an evolutionary story at the end.  But why should we do that?  To the extent that we can without sacrificing scientific rigour, we should try to uncover the evolutionary story as we go.  Not only is it damned interesting, but it can be legitimately used to constrain hypotheses in areas of the science where we haven’t yet made a lot of progress, making it a useful tool.  Besides, it’s just as conceivable that we can’t completely ignore this influence.  If nothing else, I think a basic grounding in the latest facts and hypotheses surrounding the evolutionary emergence of human intelligence should be considered an essential part of a thorough education in psychology.