Genetic determinism? Not so fast.

June 26, 2009 • 7:27 am

There are several items in the news today relevant to evolutionary psychology.  First, David Brooks, in The New York Times, has an op-ed piece on the excesses of evolutionary psychology.  Apparently “inspired” by a new book by Geoffey Miller, Brooks resists evo-psycho’s exaggerated claims:

Now Miller has published another book, “Spent,” in which he takes evolutionary psychology to the mall. The basic argument is that each of us is born with our own individual level of six big traits: intelligence, openness to new things, conscientiousness, agreeableness, emotional stability and extraversion. These modules are built into humans and other animals (apparently squid can be shy).

We are all narcissists, Miller asserts. We spend much of our lives trying to broadcast our excellence in these traits in order to attract mates. Even if we’re not naturally smart or outgoing, we buy products and brands that give the impression we are.

According to Miller, driving an Acura, Infiniti, Subaru or Volkswagen is a sign of high intelligence. Driving a Cadillac, Chrysler, Ford or Hummer is a sign of low intelligence. Listening to Bjork is a sign of high intelligence, while listening to Lynyrd Skynyrd is a sign of low intelligence. Watching Quentin Tarantino movies is a sign of high openness. He theorizes that teenage girls may cut themselves as a way to demonstrate their ability to withstand infections.

Evolutionary psychology has had a good run. But now there is growing pushback. Sharon Begley has a rollicking, if slightly overdrawn, takedown in the current Newsweek. And “Spent” is a sign that the theory is being used to try to explain more than it can bear.

This critique, along with Sharon Begley’s (see below), is a welcome sign that people won’t credulously accept the excessive claims of evolutionary psychology. Miller, in particular, has made a name (and some bucks) with ludicrous and insupportable claims about the genetic basis of human nature.  Now, Brook’s own critique is not perfect. He says, for example:

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.

But individuals aren’t formed before they enter society. Individuals are created by social interaction. Our identities are formed by the particular rhythms of maternal attunement, by the shared webs of ideas, symbols and actions that vibrate through us second by second. Shopping isn’t merely a way to broadcast permanent, inborn traits. For some people, it’s also an activity of trying things on in the never-ending process of creating and discovering who they are.

This really says almost nothing, and ignores the fact that humans certainly evolved in a social milieu, and that some of our evolved traits must have been adaptive only in a social milieu.  How else can you explain an inborn facility to learn language?  Brooks would have been better off making the most trenchant critique of evolutionary psychology:  the tendency for many advocates to make speculations completely unsupported by evidence.  Do young girls really cut themselves to demonstrate a resistance to infection? Why isn’t it young men who do the cutting? After all, it’s the men who compete for women, and the “handicap” view of sexual selection posits that ornaments like the peacock’s tail are there to show females that males have the genes or constitution able to deal with (or at least produce) a debilitating but attractive feature.  When it comes to speculations about human behavior, we also have to worry that they could have unintended social consequences. Promoting the notion that self-mutilation might be adaptive may, for example, have the side effect of promoting its spread.

Apropos, Sharon Begley of Newsweek has just published a long critique of evolutionary psychology, a critique that is surprising for a mainline magazine. Begley beings with a critique of Thornhill and Palmer’s “adaptive rape,” hypothesis, which I also attacked in a New Republic article.  Begley then discusses some data that refute evo-psycho’s more popular claims, noting that these refutations get far less press than the original, sensationalistic claims.

Evolutionary psychology is not going quietly. It has had the field to itself, especially in the media, for almost two decades. In large part that was because early critics, led by the late evolutionary biologist Stephen Jay Gould, attacked it with arguments that went over the heads of everyone but about 19 experts in evolutionary theory. It isn’t about to give up that hegemony. Thornhill is adamant that rape is an adaptation, despite Hill’s results from his Ache study. “If a particular trait or behavior is organized to do something,” as he believes rape is, “then it is an adaptation and so was selected for by evolution,” he told me. And in the new book Spent, evolutionary psychologist Geoffrey Miller of the University of New Mexico reasserts the party line, arguing that “males have much more to gain from many acts of intercourse with multiple partners than do females,” and there is a “universal sex difference in human mate choice criteria, with men favoring younger, fertile women, and women favoring older, higher-status, richer men.” . . .

Yet evo psych remains hugely popular in the media and on college campuses, for obvious reasons. It addresses “these very sexy topics,” says Hill. “It’s all about sex and violence,” and has what he calls “an obsession with Pleistocene just-so stories.” And few people—few scientists—know about the empirical data and theoretical arguments that undercut it. “Most scientists are too busy to read studies outside their own narrow field,” he says.

It’s about time something like this was published in a place where people can see it.   Bravo, Ms. Begley!

Speaking of research whose initial lurid claims get far more press than their later refutation, consider human “behavior genes.” Case after case in which researchers claim to have found genes for depression, novelty-seeking, alcoholism, schizophrenia, and the like have later been shown to be nonrepeatable in bigger data sets, or in data from other populations.  But the failures to replicate get far less media attention than do the original claims.  One example this week: a new “meta-analysis” study in the Journal of the American Medical Association that refutes an earlier claim that a gene involved in serotonin transport causes depression.    (See here and here for popular reports about the failure to replicate).  At least in this case, Newsweek (are they on a good science kick?) highlighted the refutation.  There are, naturally, evolutionary hypotheses about why genes for depression may be adaptive; I discuss some of these in WEIT.

All this goes to show that when it comes to assertions about the genetic/evolutionary basis of human behavior, caveat emptor.

37 thoughts on “Genetic determinism? Not so fast.

  1. Is it possible to clarify your position about evolutionary psychology?

    Am I right in saying you think it’s all unfalsifiable and, therefore, not science?

    Surely, how our minds got this way is worth as much attention as how our bodies did?

  2. Jerry, when you get a chance, why don’t you post on this website links to all your articles and interviews that are available on the net?

    Just a thought.

  3. ISTM that both extremes, those who try to explain each and every human behavior in terms of evolutionary just-so-stories, and those who recoil from any attempt at explaining human behavior in terms of a genetically influenced universal human nature, suffer from the same misconception. That is, they both assume that if some behavior is genetically influenced, then we are helpless, mindless puppets of our genes. That we bear no credit nor responsibility for our actions.

    I may be genetically “programmed” to see young women as sex objects, but I also have a hopefully not-to-thin veneer of culture and I am hopeful that I can act rationally and ignore the attraction I feel for them.

  4. That NEWSWEEK article is very good, but there’s one part of it that rubs me the wrong way:

    On that point, the evidence instead suggests that both sexes prefer mates around their own age, adjusted for the fact that men mature later than women. If the male mind were adapted to prefer the most fertile women, then AARP-eligible men should marry 23-year-olds, which—Anna Nicole Smith and J. Howard Marshall notwithstanding—they do not, instead preferring women well past their peak fertility. And, interestingly, when Miller focuses on the science rather than tries to sell books, he allows that “human mate choice is much more than men just liking youth and beauty, and women liking status and wealth,” as he told me by e-mail.

    This counterargument comes from Buller, and I have never liked it. Marriage is a social construct, but sexual attraction is not. Who you want to marry, and who you want to screw, are often two different things. The fact that older men want to MARRY women around their age is not relevant to the question of whether their adaptive sexual urges are geared towards younger women.

    I’m not saying that they are, just that the evidence Buller and others are drawing on here misses the point. At least, that’s how it seems to me.

    But, all in all, I agree with most of the criticism of evolutionary psychology. I roll my eyes whenever the new BS “just so” story is reported by credulous journalists. At the same time, I don’t find “It just happened” stories to be any better. Some people on the left (just like the right) really are more concerned with ideology rather than science. We are biological organisms, adapted by natural selection. There’s no getting away from that. It’s just that the evo psycho crowd is wrong about how it happened and what it means.

  5. Wes,

    Who you want to marry, and who you want to screw, are often two different things.

    Exactly. That’s why women marry the accountant and fool around with the pool boy.

  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 only, 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. thearchosaur,
    I disagree. Adaptationism does not automatically imply extreme individualism. Check out Sober and Wilson’s Unto Others. I’m not saying you have to accept their group selection theory, just that they are an example of an adaptational approach that is not excessively individualistic.

    Your summary of the “darwinian way of thinking” is an oversimplified caricature. Darwin himself would not recognize it, since he explicitly says in the Origin that he uses the term “competition” in a broad, figurative sense which includes such things as interdependence between organisms and various means of finding a mate. It’s not just “nature red in tooth in claw”. That’s a very common misconception, and it’s wrong.

  8. Exactly. That’s why women marry the accountant and fool around with the pool boy.

    Well, that’s not exactly what I meant. My problem with the thinking in that paragraph is that it uses an obvious social construct (marriage) to refute a claim about biological origins (how did our sexual desires evolve?). I just think it’s evidence from the wrong domain. If they wanted to test the sexual desires of older men, wouldn’t it be better to test some kind of autosomatic response, like showing them various kinds of sexy images and seeing what gets them the most aroused?

  9. I’m sure I put it a bit crudely, but the basic idea seems to be that the reasoned, socially constrained way that people behave for public consumption is not the same thing as what they want to do.

    Personally, I suspect that the idea that we know why we do what we do is an extremely suspect, and potentially dangerous, idea.

  10. Competition remains an important part of current thinking about selection. Remember, the malthusian argument for competition over resources? The notion is survival of the fittest: those who are better adapted.

    Selection is supposed to “improve adaptation”. How do you know adaptation has “improved”, if not by competitive diosplacement of those lacking the improvement? If probability of survival remains the same, where is the “improvement”?

    In group selection, the idea is still the same. Some unit (the group)is “selected”, outcompetes with others. I don’t think it’s the way to go.

  11. Evolutionary psych (not “psycho” Jerry. Come on) absolutely runs the risk of going too far with “just so” stories. There is also the risk, in the mad attempt to stamp it out of academia, of turning our backs on a potentially enlightening study.

    Males are nearly universally more promiscuous than females. Females are nearly universal in being more likely to marry for intelligence or wealth, as opposed to males who are much more likely to marry for youth or beauty.

    Turn your back on these facts at your peril. We’ve been down this road before, Jerry.

  12. thearchosaur
    Posted June 26, 2009 at 8:43 pm | Permalink

    Competition remains an important part of current thinking about selection. Remember, the malthusian argument for competition over resources? The notion is survival of the fittest: those who are better adapted.

    Selection is supposed to “improve adaptation”. How do you know adaptation has “improved”, if not by competitive diosplacement of those lacking the improvement? If probability of survival remains the same, where is the “improvement”?

    In group selection, the idea is still the same. Some unit (the group)is “selected”, outcompetes with others. I don’t think it’s the way to go.

    I have a number of objections to this.

    1.) You are still caricaturing natural selection. “Competition” does NOT necessarily entail direct conflict. One form might out-compete another simply by being more successful, without any direct conflict at all. This competition could involve some groups working together better than others. Darwin was explicit about this.

    2.) I don’t know where you’re getting the phrase “improving adaptation”. The word “adapt” means to be fit into something. Adaptation involves fitting organisms into the environments they inhabit. It’s a relative concept. It does not require “improvement” in any absolute sense.

    3.) “I don’t think it’s the way to go.” Well, nature doesn’t care what you think. Science is about the way the world is, not the way it ought to be.

    4.) While I am very sympathetic to the pluralist viewpoint, I still have yet to here a single anti-adaptationist explanation for how complex, functional biological components can arise without natural selection playing some kind of a role. Intelligent design, orthogenesis, Lamarckism–basically every alternative has failed. Yes, byproducts and physical constraints are important, and too often ignored, but they are complimentary rather than alternative explanations to natural selection.

    5.) By promulgating this false caricature of natural selection as if it promoted dog-eat-dog conflict, you are feeding the creationist propaganda machine. They love nothing more than spreading around false claims about Darwin causing the holocaust, and when people like you buy into these misrepresentations of natural selection, you make their job that much easier.

    1. Sorry, there were two more points I forgot to include.

      6.) A refutation of the obvious excesses of ev psych does not count as a refutation of natural selection as a whole. This “baby with the bathwater” attitude is a little irksome. Yes, the majority of what goes on in ev psych is bunk. That doesn’t mean natural selection is wrong.

      7.) Natural selection is not a moral philosophy. It is a description, not a prescription. Yes, it describes things (figuratively) in terms of competition. That doesn’t mean things should be that way. It’s just an explanation for how things got the way they are.

    2. Well said, Wes. All 7 points are on the money.

      I would like to add that arguments for ‘group selection’ could be explained as just natural selection for adaptations due to kin selection or altruism. There is little, if any, evidence of group adaptations.

  13. Wes says:

    “1.) You are still caricaturing natural selection. “Competition” does NOT necessarily entail direct conflict. One form might out-compete another simply by being more successful, without any direct conflict at all. This competition could involve some groups working together better than others. Darwin was explicit about
    this 2.) I don’t know where you’re getting the phrase “improving adaptation”. The word “adapt” means to be fit into something. Adaptation involves fitting organisms into the environments they inhabit. It’s a relative concept. It does not require “improvement” in any absolute sense.”

    I don’t think you completely grasp how darwinian natural selection relates competition to adaptive complexity.

    Since at each generation only the fittest survive, there is an ongoing process of increasing fitness. This accumulative process would not occur if resources were unlimited (e.g., in absence of competition)

    Because resources are (allegedly) always limited, competition is THE ongoing force that is constantly accumulating adaptive improvements, even in absence of environmental changes.

    This process of improvement explains the “perfecting” of adaptation to a given habita or function, their “fine-tuning” and complexity (replacing Paley’s need for a designer)

  14. Thearchosaur:

    I read your rebuttal and I thought to myself, “is he agreeing with Wes?” It reads like an endorsement.

    I think an out of hand dismissal of an approach to science because there are some idiots who tend to play fast and loose with suppositions and correlations is silly. I have often heard of someone “discovering the gene for X” only to have the claim retracted, yet I still believe in genetics.

  15. Also, Jerry, “the most trenchant critique of evolutionary psychology: the tendency for many advocates to make speculations completely unsupported by evidence.”

    Really? The most trenchant critique of a branch of science is a tendency by it’s advocates to make speculations unsupported by evidence. Well, I guess that settles it, then. Out with it. Obviously it’s wrong. Some of it’s advocates tend to speculate about it, even lacking evidence. Good thing no other branch of science does that… *cough* theoretical physics *cough*

    1. Maybe another formulation would be to say that the problem is a tendency of the popular press to run with wildly speculative claims, and a tendency of some researchers to feed the press in that way.

  16. I don’t like it when supposed darwinians don’t even know darwinism. Darwinian competition is supposed to be the driving force causing fine-tuned adaptation. As I expected, no one disgareed with what I just posted.

    Now, in truth, the argument that darwinian natural selection produces adaptation is very attractive as a logical thread of thoughts…but when you make phylogenetic comparisons and see how adaptations have ACTUALLY evolved, you realize that the statements “natural selection explains complex adaptation” is a truism that can be slapped onto any process but actually gives us no information on how real-world adaptations are involved.”natural selection did it” is about as scientifically useless as saying “god did it”. It’s more of an ideological explanation than a great scientific tool for studying the evolution of complex adaptations.

    In turn, the fact that a previously existing structure acquires a new funtion (exaptation) almost always comes up when you study the real-world evolution of complex adaptations.

    1. Oh god. Now you’ve trotted out the old “natural selection is a tautology” objection. I’m not even going to dignify that with a refutation.

      And, as I said above about spandrels and physical constraints, exaptation is complimentary, not alternative, to adaptation. Yes, natural selection involves tinkering around with pre-existing structures. That will frequently require structures being “exapted” to new functions. What processes accomplishes this exaptation? Natural selection, of course.

      And you still have not provided a plausible alternative mechanism to natural selection.

  17. My problem with ev psych isn’t so much that they speculate beyond the evidence. Speculation beyond the evidence is how scientists generate new hypotheses to test. It’s a necessary component of science.

    My problem is that they are employing a method which has been shown again and again by scientists and philosophers to be flawed. They really haven’t improved much on the old “pop sociobiology”, which Philip Kitcher showed back in the 70’s to be a completely unreliable method. I have no problem with people speculating on the evolutionary origins of human behavior–but when that speculation ignores discoveries in the past, it’s no good.

    Also, ev psych relies on some assumptions which are not only unsupported by evidence but are actually contradicted by evidence. For instance, there’s no such thing as “the” environment of evolutionary adaptedness. Archeology shows humans inhabiting lots of different kinds of environments–deserts, savannahs, jungles, tundra, mountains, etc. Despite this, we remain relatively genetically similar. This seems to me to indicate that humans are more likely to be adaptive generalists with a plastic nature which can adjust to different kinds of environments.

    Also, ev psych takes things which are certainly true in general (such as that our sexual desires are adapted in a way that we seek out suitable mates) but then runs wild with this, making very specific claims without sufficient evidence (such as that human males have a specialized “waist to hip ratio” module).

  18. As George Williams (1966) has pointed out, classifying a trait as an adaptation requires substantial evidence of efficiency, complexity, precision, functional specialization, and reliability. Contrary to your comment above, evolutionary psychology are quite aware of this.

    See:

    Adaptations, Exaptations and Spandrels, by Buss, Haselton, Shackelford, Bleske and Wakefield.
    http://www.sscnet.ucla.edu/comm/haselton/webdocs/spandrels.html

    How can we identify psychological adaptations? by Edward H. Hagen, Institute for Theoretical Biology, Berlin.
    http://www.anth.ucsb.edu/projects/human/epfaq/design.html

  19. ” …making very specific claims without sufficient evidence (such as that human males have a specialized “waist to hip ratio” module)”

    They don’t make “claims.” Instead, they develop hypotheses based on possible adaptive function(s) of a trait, and then subject those hypotheses to empirical testing.

    This is unremarkable — it is how normal science proceeds.

  20. “now you’ve trotted out the old “natural selection is a tautology” objection. I’m not even going to dignify that with a refutation”

    Huh? Never did. Way to try to bring the debate down a notch. You’ve been trying hard for a while now. I’ve just ignored you sofar, but now I’ll (briefly) answer to some of your lower thoughts.

    Your answer about exaptation is the typical sillines to comfort yourself into thinking there is nothing but natural selection going on.
    Exaptation is not a form of natural selection. This is like saying the fact I can hold a window open with a screwdriver is a fantastic example of adaptation by selection. The truth is, this happy coincidence has nothing to do with selection.

    “And you still have not provided a plausible alternative mechanism to natural selection”

    This is a primitive form of reasoning that is basically “panic to the alternatives”. You’re just assuming nothing but selection can explain adaptation, as a truism. Of course, you’re narrow minded, and dreadfully wrong.

    Exaptation is one of such mechanisms. Phenotypic plasticity is also an obvious part of explaining the evolution of adaptations that is gleefully ignored by selectionists.

  21. To be biologically plausible, evolutionary psychology should be informed by what developmental biology says about the mapping from genes to cellular structures, and by what cognitive neuroscience says about the mapping from cellular structures to ranges of behaviour. Often enough, it ain’t.

    My own suspicion is that we will have a truly solid evolutionary psychology at about the time we have Strong AI.

    1. I actually think there are better prospects than that.

      Whenever any science is in its infancy, there will be a lot of bullshit floating around. Just look at evolutionary theory as a whole in the 19th century. Evolutionary psychology might be no different in that regard. Part of the problem is that, without well-established methods and criteria, sifting the good stuff out of the bullshit can be difficult.

      It seems to me that an evolutionary account of psychology is clearly possible, but just what it would look like is not so clear. And until it becomes more clear, there will be a lot of growing pains.

  22. I think Blake Stacey is right on the money. The problem is evolutionary psychologists don’t care to understand any actual biological and developmental mechanisms, so long as they can have an “evolutionary” explanation, that is, one in terms of some selective advantages of genes that “must” exists.

    Case in point? I just had an apologist of adaptaionist evolutionary psychology tell me that women can smell symmetry on a man. From their adaptationist point of view, it makes perfect sense (symmetry is “desirable”)

    But I’m thinking, this implies some fantastic mechanism of production and recognition of odoriferous molecules that signal symmetry. I’m thinking a statistics artifact is more likely here than the existence of such a mechanism.

    Would you think evo psych even WORRY about the implications in terms of biological mechanism? Do you think they will set out to prove it? Nope. They are happy to forever remain in the soft science, the preliminary level of mere statistic correlations

  23. Sorry, I don’t get all this negativity about evolutionary psychology. Granted, many journalists present research results as “just-so stories”, simplifying too much. And I agree that there isn’t enough evidence (yet) for many claims about EP. There is still much room for improvement, and many evidence to gather.

    What is completely false, however, is that evolutionary psychology theory satisfies itself with “just-so stories” and is not interested in the underlying mechanisms. If you pick up almost any book on EP theory, you’ll find a consistent and remarkable case that EP should concern itself with mechanisms (they call it modules), and how they work. They don’t simply assert, “well, I guess there is a module for that behaviour”, but try to explore the (algorithmical) structure of such a mechanism, via reverse engineering (provided there is enough reason to suggest such a mechanism exists).

    I agree however with what a poster said before – EP could and should take advantage of modern techniques in cognitive research (structural equation modeling for starters), and computer simulations, to become a truly XXI century science.

    1. EP has very little regard for underlying biological mechanisms. Yes, they speculate about modules, but they do not care to understand the neurobiological systems in a way that would provide evidence for said modules. Just because there is evidence that parts of the brain are in fact ‘modular,’ does not mean that the entire nervous system works that way – there is an overwhelming amount of neurobilogical evidence that clearly shows it does not. This field has been attacked by neurobiologists for this reason.

      Yes, this field does often engage in empirical (soft-science) research, but only after they have made tremendous leaps in logic… the research and interpretation is then tainted and has little value.

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