Evolution for Everyone

Only one reason for ignoring the E-word remains to be considered:

All branches of knowledge should ideally be consistent with each other, but every branch need not be consulted for the study of any particular branch. I rarely feel the need to consult quantum physics when I study evolution, and perhaps evolution rarely needs to be consulted for the study of many traits, in humans and nonhumans alike.

It’s true that each of Tinbergen’s four questions can be studied in isolation, but the essence of his essay describing the evolutionary perspective is that they are best studied in conjunction with each other. Moreover, what’s true for an individual is not true for an entire discipline, as I discussed for the study of proximate mechanisms in the previous post. I therefore conclude that all four reasons for ignoring the E-word fail to pass muster after they have been respectfully considered. Tinbergen’s four-question approach needs to be applied to any sizeable human-related subject, just as for any sizeable subject in the biological sciences.

I would like to think that a consensus can be quickly achieved on this matter, but a recent exchange on the relevance of evolution for the field of social psychology indicates that a consensus is a long way off. The exchange appeared on the Edge website in response to an essay on social psychology by Timothy D. Wilson, who happens to be my cousin. Tim included some comments on evolutionary psychology in his essay, which moved Steve Pinker to reply and Dan Gilbert and Hugo Mercier to join the fray. It is worth examining Tim’s essay and the exchange in detail, because it represents the state of play at the highest level of expertise. If these folks can’t agree on what evolution has to do with it, a broader consensus is indeed a long way off.

Social psychology is an excellent example of a human-related discipline that arose in the 1950′s and developed without explicit reference to evolution. By Tim’s own account, social psychology offered an alternative to behaviorism and showed how rigorous scientific methods could be used to study how the mind works in a social context. Tim himself finds it difficult to define the field and ends up listing a number of research programs, such as conformity, obedience to authority, affective forecasting, stereotype threat, and the fundamental attribution error. Tim also stresses that social psychology can contribute to the solution of real-world problems, although he acknowledges that its insights should be applied more actively in the future than in the past.

Tim received his PhD in 1977, just after the publication of E.O. Wilson’s Sociobiology, so his career path runs in parallel with the modern history of evolution in relation to human affairs. His PhD research with his mentor, Richard Nisbett, became a classic paper titled “Telling more than we can know: verbal reports on mental processes” and initiated a line of research on unconscious processes that is summarized in Tim’s 2002 book Strangers to Ourselves: Discovering Our Adaptive Unconscious. His next book, titled Redirect: The Surprising New Science of Psychological Change, will be published later this year.

It’s wrong to say that Tim Wilson doesn’t think about evolution. In fact, when I read Strangers to Ourselves, it struck me as an independent derivation of the field of evolutionary psychology. Tim said that there is an unconscious but it’s not what Freud had in mind. Instead, it represents complex mental processes that evolved by genetic evolution and will forever remain inaccessible to introspection. The only way to understand it is by studying it scientifically, as he and his colleagues in social psychology have been doing over the decades. Their inquiry is replete with speculation about the function of the subconscious processes that they are studying, which informs their empirical research.

Tim pays almost no attention to the self-described field of evolutionary psychology in Stranger’s to Ourselves. The neglect is reciprocal. In my experience, the only paper by Tim and his colleagues cited by self-described evolutionary psychologists is his 1977 classic with Dick Nisbett. I am confident that a proper citation analysis would reveal very little intellectual exchange between Tim’s world of social psychology and the self-described field of evolutionary psychology–even though Tim and his colleagues have become evolutionary in their own way.

The gulf between these two academic disciplines is apparent in the “strangers to each other” feel of the exchange on Edge. When Tim criticizes evolutionary psychology, it is the self-described field of evolutionary psychology that he frankly doesn’t know very well. His observations include the following:

• “There’s a very loose kind of theorization that goes on, where people just tell a story and assume that it’s true because it kind of makes sense.”

• Evolutionary psychology has become “the new psychoanalysis” that vacuously claims to explain everything.

• Like Freudian theory, evolutionary psychology has led to a lot of absurd conclusions that are hard to test rigorously.

• Like Freudian theory, evolutionary psychology is “obsessed with gender differences.”

• The “storytelling method” is irredeemably speculative. Tim gives an example of the color of blood as a byproduct rather than an adaptation and proceeds to give an adaptationist explanation that he regards as just as good, or at least immune to empirical test.

• On a positive note, Tim cites the work of Jon Haidt on moral psychology, which somehow escapes the weaknesses of the rest of evolutionary psychology. He also credits the evolutionary perspective for making a worthwhile contribution to the study of religion (perhaps a nod to his cousin!) and ends by emphasizing the role of narratives in religious (and other) meaning systems, which is the subject of his forthcoming book.

I invite the reader to compare Tim’s comments with my own consideration of “what’s evolution got to do with it?” in this series of posts. At best, Tim is accurately commenting on the particular way that the self-described field of evolutionary psychology has developed. At worst, he is grossly misrepresenting a literature that he doesn’t cite in his own work and therefore doesn’t understand. His blood example is especially silly and is easily dispatched by Steve Pinker. The fact that Tim is more charitable on the topics of morality and religion, with which he is a little more familiar, should make us cautious about the rest of his critique.

Among the many problems with Tim’s critique is the ghost of genetic determinism. Here is what he says about the climate of opinion when he received his PhD:

In the late ’70s, if a social psychologist were to say I’m an evolutionary theorist, that would have been a really taboo thing to say. It would have struck people as overly deterministic, and perhaps even sexist, to look at gender differences in social behavior as somehow inherent in the human condition.

Tim’s leap from “evolution” to “determinism” to “sexism” speaks volumes about where social psychology came from as a discipline, from which it has not yet fully recovered. Evolution is required to explain our capacity for social constructivism and its products, just as much as the aspects of our behavior that can be attributed more directly to genetic differences.

In his comment on Tim’s essay, Steve Pinker rightly objects to the charge that evolutionary science can’t be as methodologically rigorous as any other kind of science. This charge has become so common as a way to quickly dismiss the evolutionary perspective that is qualifies as a “just-so story” in its own right. It also confuses the role that evolutionary theory plays in the re-organization of given field such as social psychology. Consider Tim’s own use of evolution to re-organize the study of unconscious mental processes. Before, we had the Freudian conception of the unconscious. Thanks to Tim and his colleagues, we have a new conception based on automatic mental processes that evolved by genetic evolution. The new conception results in a re-organization of existing information and a new agenda for guiding future empirical research–using the exact same methodological toolkit that was being employed before. Some hypotheses will be more difficult to test than others, but that comes with the territory for any sizeable biological or human-related topic. In his comment, Hugo Mercier also uses Tim’s own work to make a similar point.

After defending the evolutionary perspective, Steve Pinker lodges a criticism against the field of social psychology, to which Tim and Dan Gilbert object. This might seem like your average turf war, but there is an important issue at stake that I would like to see all parties agree upon. There is a certain arbitrariness to the research programs that comprise the field of social psychology. Particular foci come and go with no particular rhyme or reason or relation to each other. Even Tim found it difficult to define the field and quickly resorted to a listing of research programs. This is not a pot shot; it is an accurate observation about social psychology and many other human-related disciplines.

Take the topic of Machiavellianism, which became a hot topic in social psychology in the 1970′s and now merits only a paragraph in current social psychology textbooks. It was initiated by a social psychologist who had the bright idea that the kind of personality associated with Machiavelli might be an interesting individual difference to study and went on from there. Another topic within social psychology was sociopathy, which generated its own literature in isolation from the literature on Machiavellianism, until someone noticed that they are largely overlapping constructs. Both were eventually reviewed and synthesized from an evolutionary perspective by myself and my colleagues (for Machiavellianism) and Linda Mealey (for sociopathy) as part of the much larger topic of cooperation and conflict in human social interactions. There is nothing arbitrary or faddish about cooperation and conflict. It will always claim a large section of an evolutionary social psychology textbook because it is so fundamental to the behavior and cognition of humans and every other social species.

Pointing out the arbitrariness of research programs within social psychology and the more unified nature of evolutionary social psychology is not a cheap shot; it’s a legitimate observation that Tim implicitly acknowledges in his own account and needs to be addressed in a conversation on “what’s evolution got to do with it?”

Having critiqued social psychology, I need to give equal time to the self-described field of evolutionary psychology. One of my most difficult tasks, when talking about evolution to a broad audience, is to distinguish the evolutionary perspective writ large from the ideas of particular people such as Leda Cosmides, John Tooby, Steve Pinker, and David Buss. I have always had a love-hate relationship with their particular formulations, which I have expressed in many academic articles and for a general audience in my own forthcoming book The Neighborhood Project. To focus on the hate part, it was a great error to portray evolutionary psychology and “the standard social science model” as black-and-white alternatives. Ever since, it has been a struggle to portray the open-ended capacity for individual and cultural change associated with behaviorism and social constructivism as part of evolutionary psychology.

For the purposes of this post, the most important take-home message is not that the evolutionists already have everything figured out. It is that the evolutionary perspective provides a toolkit for scientific inquiry, nicely summarized by Tinbergen’s four questions, that is required for all sizeable subjects in the biological and human-related sciences. Ever the optimist, I would love to think that experts such as Tim, Dan, Steve and Hugo can agree on this point, as the first step toward a broader consensus. If so, then the absurd fact that evolutionary psychology and social psychology continue to inhabit parallel universes can become a thing of the past.


  1. #1 B. Weeks
    June 19, 2011

    After reading the Pinker/Wilson exchange on Edge, I was shocked at Wilson’s lack of basic knowledge of evolutionary biology. I know he is a psychologist but still…he’s a scientist. No wonder evolutionary psychology seems ridiculous to him. Pinker shows what a little “consilience” can do for psychology.

  2. #2 Reinste ventures
    June 20, 2011

    Thanks David Sloan!
    Your article is quite very informative and interesting. Each detail is defined very deeply. I love it and hope u will come again with another new article.

  3. #3 sohbet odasi
    June 21, 2011

    tsk ederim

  4. #4 Michael Blume
    June 26, 2011

    Thanks for that one, David! The lack of interdisciplinary dialogue even “within” the expanding field(s) of evolutionary studies might indeed constitute a major problem of the future. When people start to form distinct “traditions” ignoring each other (such as seems to happen with many evolutionary and social psychologists), a loss of scientific output and credibility might result. Maybe blogs can help to “bridge some gaps” here.

  5. #5 Brad
    June 30, 2011

    I agree that the lines drawn between the purported ‘SSSM’ and evolutionary psychology (EP) are problematic. However, the field of EP, just like most theoretical paradigms, have certain theoretical assumptions either explicitly or implicitly guiding their hypothesis testing. Their assumptions are thought to be ‘true’ as far as they are concerned… if we don’t buy into the way THEY view evolution to have shaped the mind, then we must be social determinists in their eyes since there is no other way of viewing the human mind from an evolutionary informed perspective. But conceiving the evolved mind to be an an information-processor with innately pre-specified and domain-specific programs shaped by natural selection… is only one way of doing this. There are alternatives.

    I do not think you can integrate EP with some of these other perspectives, because their theoretical assumptions are so different. In either case, until EP either dies out or succeeds in unifying the social sciences (their stated goal), I would prefer that writers distinguish between evolutionary psychology (the field with these specific information-processing theoretical assumptions) and evolution as applied in other ways to explore human psychology.

  6. #6 David Sloan Wilson
    June 30, 2011

    Thanks to everyone for their informative comments. In response to Brad, the challenge is to reconcile the fact of elaborate innateness (emphasized by EP) with the fact of elaborate open-ended flexibility (emphasized by the SSSM). The immune system already offers a well worked out example where these two seeming opposites are reconciled, and the study of human behavioral and cultural flexibility can proceed along similar lines. This is one theme of my forthcoming book The Neighborhood Project, which will be out in August.

    This kind of reconciliation is already in progress, if one knows where to look. For example, evolutionary developmental psychologists such as Bruce Ellis have proposed a model that they call the Adaptive Calibration Model (ACM) of Stress Responsivity, which specifies how the stress response system interacts with the environment during development to calibrate the phenotype of the organism to its environment–or at least to its ancestral environment. The ACM model is very much in the spirit of the innate and adaptive components of the immune system.

    Although it might seem merely semantic, I think it is essential to reserve the term evolutionary psychology for the study of psychology from an evolutionary perspective writ large. The views of folks such as Cosmides and Tooby are schools of thought within evolutionary psychology. Their views became so prominent in part because they were able to capture the term. Once they are seen as merely schools of thought, their (partial) rejection can be seen as science in action rather than a failure of evolutionary thinking.

    Terms such as “evolution”, “group selection”, “sociobiology” and “evolutionary psychology” have all been stigmatized in the past for what they seemed to represent. There is a natural tendency to avoid associating with a stigmatized term, no less than with a stigmatized person. Yet, the long term consequence of avoiding the terms is endless confusion. It is an intellectual tragedy of the commons. It’s much better to develop a detailed scholarly knowledge of the past and to distinguish the broad subject areas defined by these terms from mere schools of thought within the subject areas.

  7. #7 Joel
    July 26, 2011

    I found Steven Pinker’s response to be thoughtful and measured, but I recall him taking an opposite stance not long ago with Daniel Dennet on the encroachment of evolutionary thinking into cultural/psychological domains. His argument was that the evolutionary principles that gave rise to organismal complexity have a non-linear relationship with cultural complexity because the mechanisms of selection are different. Namely, that darwinian selection follows from blind mutation and environmental selection where cultural complexity is instead “Lamarckian”, that is to say, cultural innovation derives from felt need and successive, purposeful reiteration with deliberate improvement. While I don’t think this detracts from the notion that we can (*and should*) borrow from an evolutionary tool-kit to explain social complexity, I don’t think Brad’s concerns about teat-totaling axioms across disciplines without taking stalk of the considerable distance involved is trivial.

  8. #8 Ovidiu C
    August 20, 2011

    Yes, Evolution puts everything on this planet into a plausible perspective- it is the red thread into our ultimate genealogy, putting a TV series like “Who do you think you are?” to shame! I am quite amused when I hear my Australian friends talking proudly about their genealogy findings that they can claim a convict as their great- great- granddaddy; but why is it, I ask myself, that they hardly ever want to know more about our primeval common ancestors, deep down into a million millennia? And why is there such scant human interest in those members of our human race- the indigenous people, that can authentically claim to have the genealogically purest lineage , going back – not 150, but 50 thousand years?

  9. #9 hazel-rah
    August 20, 2011

    Ah… it’s always a sign that a conversation is going in a productive direction when the words “genealogically purest lineage” show up.

    C’mon… really? People of all sorts have been claiming a “pure” (and, of course, ancient) pedigree for centuries and it has lead to nothing but misery and ignorance. This argument that indigenous Australians are more closely, genetically related to Pleistocene ancestors contributes precisely nothing to their causes or ours. It ignores their own histories and kinship systems. Typically, it primitivizes their lives as modern examples of stone-age practices. And (as you do here) it positions common ancestry as an ideology through which we might all learn to respect each others’ diversity while (ultimately) falling back on our genetic similarity. What would be the purpose of pursuing such a line of thought?… It merely raises Darwinism to the level of religion, with all the latter’s abstractions and aims toward universal acceptance. In short, quite lame.

  10. #10 Logan
    August 20, 2011

    It’s not that it is wrong to ask about contextual histories in explaining psychological phenomena, or that one must, like, burn non-evolution evidence in a fire. it’s just that, at some point, you must ask yourself WHY the societal/political/psychological precursors existed as they did in the first place?

    the answer to this will always invoke evolution, since evolution is the causal force that produced the genetic and epigenetic profile which necessitated (in the relevant environment of course) the psychological/social structures. ultimately, it is incoherent to think of psychology or society as “causes” of human behavior in any general sense, because they ARE human behavior and must therefore themselves be explained in terms of evolutionary forces if evolution theory is to be sensible.