Friday, June 26, 2009

Why Evolutionary Psychology Is False

I haven't got time to review the recent publications on evolutionary psychology. The good news is that the popular press is finally waking up to the fact that the entire field is suspect. It sure took them long enough.

Read a summary on Why Evolution Is True: Genetic determinism? Not so fast.


  1. You can say things like "Why the scientific method isn't being applied rigorously enough to evolutionary psychology", but I don't see what makes the entire field false, I mean ultimately there must be an evolutionary reason for things.

  2. So, Larry, do you still think that research into genetically determined differences of intellgence between races is being blocked by political correctness?

    Funny since so much research on this topic HAS been made: kuch of it was de-bunking done by stepehen jay gould. remeber, once the BASE ASSUMPTION used in science was that racial differences were correlated with genetically inferior inteligence.
    The result of this research IS available and it is plain and simple: there is no evidence for genetic differences of intelligence among races.

  3. Larry: "Why Evolutionary Psychology Is False"

    You mean everything? Really? EVERYTHING?

    The idea that natural selection can act on psychological traits has been proven false? Really? REALLY?

  4. Divalent,

    I'm sorry if the deliberate use of hyperbole confused you.

    Have you left a comment on Jerry Coyne's blog where you point out the obvious? Not everything in evolution is true.

    And while we're at it, let's be careful not to say that Intelligent Design Creationism is false because I know of at least one thing in Michael Behe's books that's true.

  5. You say evolutionary psychology is false, but I think it is important to remember the thoughts of Gould on the subject: an evolutionary psychology is very desirable in theory, but its current incarnation as an adaptationist program is faulty.

  6. “The second problem is one evolutionary psychology shares with economics. It’s too individualistic: individuals are born with certain traits, which they seek to maximize in the struggle for survival”

    This is not only a valid criticism for evolutionary psychology, but also for most evolutionary ecology (and specially, most behavioral ecology)

    The darwinian way of thinking centers on the process of natural selection and sees “gain” and “improvement” whose most clear manifestation is competitive superiority over others.

    This leads directly to the selection-centered adaptationism of evolutionary psychology, which is simply applying these notions to humans. The exact same way of thinking is used by many ecologists in their non-human studies. As Gould and lewontin documented, the speculation going on there can be as bad and ideological as what we see in evolutionary psychology. I guess we just don’t perceive it as sharply as in Humans (nor are the topics as sensitive in non-humnas)

    The problem is not that evolutionary psychology, specifically, is wrong: its roots, adaptationist evolutionary biology, is what wrong.

  7. I agree, but sometimes I think people take the competition vs. cooperation metaphors too seriously. It's not as if, in reality, organisms actually compete (or if they do, its rare), and cooperation doesn't seem to be some conscious choice (though it certainly is in humans, and probably is in apes as well; see the work of De Waal).

  8. Several weeks ago, Dr. Moran asked me via email to provide him a single valuable or interesting finding that has been generated via the evolutionary psychology field. At first, I refused to do so, as I told Larry that it was frankly outrageous to posit that of the countless articles that have been produced via this framework, not a single one could pass his "lofty" threshold. Larry retorted that my refusal to provide him with a single example should be taken as a confirmation of his low opinion of the EP field.

    I decided to then take up Larry's challenge and accordingly I sent him the following list:

    (1) Women alter their preferences for the facial features of men as a function of where they are in their menstrual cycles. When maximally fertile, they prefer men possessing markers of high testosterone.

    (2) Babies display an immediate instinctual preference for symmetric faces (at an age that precedes the capacity for socialization).

    (3) Children who suffer from congenital adrenal hyperplasia display a reversal in their toy preferences. Furthermore, using inter-species comparisons, vervet monkeys display the same sex-specific patterns of play/toy preferences as human infants. This suggests that contrary to the argument made by social constructivists, play has an evolved biological basis.

    (4) Individuals who score high on an empathy scale are more likely to succumb to the contagion effects of yawning. This is indicative that this particular contagion might be linked to mimicry and/or Theory of Mind.

    (5) How provocatively a woman dresses is highly correlated to her menstrual cycle (a form of sexual signaling found across countless Mammalian species).

    (6) Culinary traditions are adaptations to local niches. For example, the extent to which a culture utilizes meat versus vegetables, spices, or salt is a cultural adaptation (this is what behavioral ecologists study).

    (7) Maternal grandmothers and paternal grandfathers invest the most and the least respectively in their grandchildren. Whereas all four grandparents have a genetic relatedness coefficient of 0.25 with their grandchildren, they do not all carry the same level of "parental uncertainty." In the case of maternal grandmothers, there is no uncertainty whereas in the case of the paternal grandfather, there are two sources of uncertainty. This last fact drives the differential pattern of investment in the grandchildren.

    (8) Good male dancers are symmetric (paper published in Nature). One would expect that some behavioral traits might correlate with phenotypic quality as honest signals of an individual's desirability on the mating market.

    (9) Self-preference for perfumes is linked to one’s immunogenetic profile (Major Histocompatibility Complex).

    (10) When a baby is born, most family members (especially those of the mother) are likely to state that the baby looks like the father. This phenomenon is found in countless cultures despite the fact that it is objectively impossible to make such a claim of resemblance. The reason for this universally found cultural tradition lies in the need to assuage the fears of paternity uncertainty.

    (11) Environmental stressors (e.g., father absence) and the onset of menarche (first menses) have been shown to be highly linked. In numerous species, the likelihood of a female becoming reproductively viable is affected by environmental contingencies.

    (12) Women are less receptive to mandatory hospital DNA paternity testing (for obvious reasons). In other words, their willingness to adopt a new product/service is fully driven by an evolutionary-based calculus.

    (13) Women can smell the most symmetric men. In other words, women have the capacity to identify men who possess the best phenotypic quality simply via their nose. This is what I have referred to as sensorial convergence.

    I shall continue part 2 below (length restriction).

    Gad Saad

  9. Continuing my comment:

    (14) Using fMRI, the exposure to ecologically-relevant stimuli (e.g., beautiful faces) yields distinct neural activation patterns in men and women.

    (15) In choosing a mate, humans tend to prefer the smell of others that are maximally dissimilar to them along the MHC. This ensures that offspring possess a greater "defensive coverage" in terms of their immunological system.

    Are none of the latter findings even remotely interesting or valuable? Are they all a bunch of silly nonsense?

    I then advised Larry that if he were to read my book (The Evolutionary Bases of Consumption), I discuss endless other examples that might peak his interest.

    Larry had promised that he would post on his blog any examples that I might send him. Not only did he not keep his promise, he never bothered to reply to me.

    Incidentally, those of you who are interested might wish to check out the following rebuttals to Sharon Begley' s article:

    My Psychology Today post:

    David Sloan Wilson's post:

    I am probably wasting my time putting up a comment on Larry's blog as it feeds his need for attention. Nonetheless, I wanted to set the record straight about Larry's etiquette (or lack thereof) regarding intellectual discourse.


    Gad Saad

  10. It seems to me that you lost, Larry! Gad has pointed out that EP is a more than just promising approach and that there exist scientifically proven evidence for its paradigms.

    Why don't you try to prove that there is no god! Might be a more promising field for you. Start with reading some Immanuel Kant....


  11. Larry said: "Divalent, I'm sorry if the deliberate use of hyperbole confused you. "

    Well, with good reason, as it is consistent with your other comments on the topic. Which was immediately reinforced by Gad Saad’s comment that you challenged him to provide a single valuable or interesting finding that has been generated via the evolutionary psychology field. Your view seems perfectly stated in that question. (Even if there was no such findings to point to, that would only highlight the lack of productivity, not the legitimacy, of the field.) And your analogy to ID is strong confirming evidence of that view: you really do think (as do I) that ID is not legitimate science and so the only reasonable interpretation is that, by making that analogy, you feel similarly about evo-psych. So if I am confused about your position, it is your own fault.

    There are strong reasons to expect that many important human behaviors are ultimately adaptations. The strongest argument along those lines is the clear evidence that similar behaviors in other animals bear the strong signature of being genetically based and plausibly adaptive: behaviors in social animals (from insects up to mammals), differences in behaviors across species, and the ability of breeders to select for behavioral traits in domesticated species. Given that evidence, what reasons exist to suggest that humans would be exceptions? Although it is almost certainly the case that human brains have the largest “all-purpose computing” capacity, there is no reason to think humans are any more than just quantitatively different.

    The evidence doesn't necessarily have to depend on identifying specific genes. For example, can there be any doubt that a human's ability to want to have sex with a member of the opposite sex is a genetic adaptation, despite our current inability to specify the genes that give rise to that ability?

    It seems like the greatest resistance to biological research arises whenever the target threatens the prevailing socio-political model of human nature. In the 19th century, it was the special status of humans in God’s creation. More recently, the blank slate theory underlies the hope that the human condition generally, and human inequality specifically, can be improved by merely modifying our environment. This view is threatened by theories that proposed a role for a genes in human behavior. No one objected to the general theory Wilson outlined in Sociobiology on the basis of evidence mostly derived from the study of animals until he took the next logical step and suggested it would be relevant to humans as well. (Then entered Gould and Lewontin to vigorously oppose it as illegitimate science and try to kill it in the crib.)

    I do understand the resistance to speculatory pop-psychological explanations of various human behaviors, but I really don’t understand your repeated ridicule of the field as a illegitimate scientific enterprise. It is, and will be, a difficult area to study: much like evo-devo is an order of magnitude more difficult to study beyond Mendelian-like traits, evo-psych will be an order of magnitude further more difficult. Keeping in mind the adage that 80% of everything is junk, criticisms that challenge the legitimacy of a whole field of inquiry should be directed at the strongest, not the weakest, evidence that supports the program. Sniping at the “toenail-painting gene” may be fun and legitimate, but only as a criticism against that particular target.

  12. Divalent, here are my actual words from our email conversation. You will note that they are not exactly the same as the words that Gad puts in my mouth.

    P.S. Can you give me a few examples of the "great, profound, and valuable works" that have been done by evolutionary psychologists? I can't think of any.

    Of course I don't think that every bit of research done by psychologists is bogus, nor do I think even think that all work on the evolution of human behavior is entirely without merit.

    However, the field as a whole has not exactly impressed me with the overall quality of the "science" that's being done. I think it's quite fair to say that the reputation of the field is not great. The present of a minority of good scientists isn't going to change that impression very much.

    One of the things that Gad and I discussed is the apparent lack of self-criticism within the field. There don't seem to be a lot of evolutionary psychologists speaking out against the excesses of the majority. Instead, they spend most of their time tying to defend the discipline by picking out the few papers that represent good science. This isn't going to work.

    It's true that every field has its kooks publishing things that should have never seen the light of day. The problem with evolutionary psychology is that the kooks seem to be running the asylum. Unlike other sciences, you have to look hard for the sound, legitimate, science and not for the rare examples of bad science.

  13. So...are we to assume that you have nothing in particular to say about the specific research referred to in Gad's post? Or, are we to just uncritically accept your assertion that "evolutionary psychology is false"? That's really a pretty silly statement. No scientific discipline is "false"...there are only supported or unsupported hypotheses generated by theory. The research referenced by Gad is a smattering of hypotheses that were generated by evolutionary theoretical approaches to human behavior. They do not make evolutionary psychology "true", "false", or otherwise. Sexual selection theory, parental investment theory, kin selection theory, etc. have all been shown to meet the three basic criteria for scientific theories: 1) utility, 2) parsimony, and 3) falsifiability. Repeated assertions that "evolutionary psychology is false" is really not a critique worthy of a scientist. It sounds more like something a journalist for Newsweek would conjure up.

    If you'd like to get yourself acquainted with the "self-criticism" amongst scientists who apply evolutionary theory to human behavior, you really should attend one of the annual meetings of the Human Behavior and Evolution Society (HBES) that you hastily dismissed in a previous post. There you will find biologists, psychologists, sociologists, anthropologists, economists, and a wide assortment of other professionals involved in research including human behavioral ecology, cognitive anthropology, behavior genetics and, yes, evolutionary psychology (even though this latter phrase has come to be shorthand for the general field). There you will find vigorous, vigorous debate and an abundance of criticism and critical thinking.

    I've never understood Jerry Coyne's (or, Begley's) critique of Thornhill and Palmer's book on human rape. While I can understand the opposition to the view that evidence supports an adaptationist interpretation of this type of behavior, they consistently de-emphasize the fact that the co-authors of the book disagreed BETWEEN THEMSELVES whether the evidence supported this interpretation and this is clearly covered in the book. Are we not allowed to even have this debate? If hypotheses are informed by adaptationist logic, is this prima facie evidence that they are "false"? Reasoned hypotheses are not "just-so" stories.

  14. Here's some relevant reading

    Why Evolutionary Psychology is “True”: A review of Jerry Coyne, Why Evolution is True,
    by James R. Liddle and Todd K. Shackelford

    Also, curious as to what Larry think is correct in Behe's book... should be interesting.

  15. Also, curious as to what Larry think is correct in Behe's book... should be interesting.

    I think Behe's view on common descent is one example. see this link: