Troubles with Evolutionary Psychology

One of the two most common counter-arguments to critiques of marriage is “but monogamy/coupling is natural!” (The other is “but it’s best for the children!” which I will not address here). As a marriage critic, I found that more of a challenge than a convincing counter, so I decided to investigate. Before I share what I found on that topic I want to provide some background information. Most of the claims that monogamy is not natural come from evolutionary psychologists, so I figured looking at that is a first step.

I agree with Frans de Waal who suggests that the troubles in evolutionary psychology (EP) stem from a lack of understanding of evolutionary theory in general, which is hardly taught in U.S. schools (thanks to the religious wrong). Though the goal of EP is admirable – “to provide an evolutionary account of human behavior” – the approaches tend to ignore some important evolutionary aspects. De Waal identifies several mistakes made within EP: (1) Assuming that anything genetically influenced must serve a purpose; (2) investigating single traits out of context; (3) ignoring the norm/focusing on rare behavior; (4) ignoring evidence from other areas, primatology and neuroscience in particular. Based on an analysis by Jerry Coyne of Steven Pinker’s suggestions around a cognitive niche, we can add a few more problems: (5) we cannot exclude other theories through tests; and (6) the promising tests are ethically troublesome.

Let’s take a closer look at these more closely. There are many diseases that have genetic bases – for example thyroidism has at least some genetic aspects – but that does not mean that they have a purpose. In fact, evolution itself is purposeless – there is no ultimate goal. This is closely tied to problem 2: Often traits are side-effects of other characteristics, so if we only look at a single trait, we either miss the evolutionary significance or misconstrue it. De Waal gives the example of our upright posture. As anybody who has ever had back-problems knows, there is a cost to that posture. Obviously, it must have had some benefit for species survival, otherwise we would be on all fours. But it’s not a trait that by itself can be explained as evolutionary beneficial. Ignoring common behavior led evolutionary psychologists to the absurd (and offensive) claim that rape is evolutionary beneficial. Say what?!? Instead of trying to explain the minority behavior, we should look at what most people do: Not rape. Rape is also a good example for another troubling aspect of EP, which plays into problem 4: Ignoring evidence from other areas (see also this review of the book). In this case, psychology, sociology, or women’s studies could help us understand rape as something more complex as a “rape gene,” or whatever biological basis is claimed in that book.

As Anne Fausto-Sterling keeps pointing out – especially in her Bare Bones articles – we have to take a systems approach to explain human behavior (or bone structure, as Fausto-Sterling eloquently argues). Human behavior is too complex to reduce it to a gene or two. Rape could be viewed from a genetic and a power perspective, for example. Both de Waal and Jaak and Jules Panksepp call for evolutionary psychologists to look at the evidence from animal and brain sciences. EP seems rather enamored with the human animal and thus comes to conclusions that often contradict what we know from neuroscience, for example. Panksepp & Panksepp point out that much of our behavior is driven by parts of the brain that evolved long before homo was even on the scene, thus cannot be unique to humans. Similar points have been made by Elisabeth Lloyd and Marcus Feldman (the response by two evolutionary psychologists did not convince me).

Coyne points to genetic testing troubles. His arguments almost suggest that EP might be untestable, and thus unfalsifiable, because the DNA evidence is inconclusive – we cannot rule out alternate theories – and between species gene-transplant tests – promising to be more conclusive tests – might not be ethically feasible between primates and humans (though as some commentators pointed out, Coyne does not advance an argument for this).

Overall, the most troublesome critique of evolutionary psychology really comes from Fausto-Sterling, though she does not make this critique explicitly. EP ignores the interaction of lots of different factors. This will become clearer when I tackle the question “is coupling natural?”

If you know about any EP work that leverages system theories, please let me know! I really think that’s the way we need to approach the origin of human behavior… The Origins Project at ASU might be a step in that direction – it is very interdisciplinary (see also here).






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Troubles with Evolutionary Psychology — 16 Comments

  1. Pingback: Rachel’s Musings » Is Coupling Natural?

  2. Pingback: Rachel’s Musings » Lehrman on Lorenz’s Theory of Instinctive Behavior

  3. You are right, Justin, that culture is not synonymous with environment. However, in my mind, cultural influences are part of the environment. That is particularly obvious in the case of lactose tolerance, which only evolved when an agrarian life style was adopted and then only when milk became one of the primary sources of nutrition (for example, the mutations did not happen in Mongolia).

  4. I will concede that the picture that evolutionary psychology paints of human behaviour is one of black and white and not of colour. Steven Pinker does acknowledge that there are other factors that influence the expression of genes in humans, but he seems only to mention those that are internal (i.e., other biological/chemical events taking place in the body) and not external (i.e., environmental). Admittedly, this is a bias of his but I think it has more to do with the lack of concrete research on environmental effects on gene expression than Pinker’s inexorable endorsement of the “nature” or “genetic” position.

    The link you provided seems very interesting and I will be sure to share my feedback with you after I listen to the whole podcast. However, in the mean time, I think I should address something. “Culture” is not synonymous with the “environment”, as many of effects that the later exert on gene evolution are part of natural selection (i.e., the weather, geographical conditions, food availability). Culture, as I understand it, is a collection of beliefs, ideologies, customs, practices, languages, and technologies of a particular geographical region that govern the way in which inhabitants of that region interact with one another socially. Human’s capability of understanding and following the traditions of a given culture is universal and is only possible because of the cognitive faculties that our minds possess (which were shaped by natural selection).

    So culture, as I understand it, cannot influence the evolution of genes because it is a by-product of our genes. It can, and certainly does, shape the way we think, feel, behave, and live our lives, but all of these abilities (i.e., to think, to feel, to perceive etc.) are the result of natural selection, not culture. Although culture may have an impact on how these abilities are performed, it played no role in their evolutionary development. Or at least this is what I believe. I stand to be corrected and remain open to alternative theories.

  5. I just listened to an interesting Scientific American podcast episode on human evolution. It included fascinating details on the evolution of lactose tolerance, which happened at five different geographic areas with probably four different mutations about 5000 years ago (assuming I remembered the numbers correctly 😉 ). This is a prime example of culture impacting gene evolution… The podcast also includes an interview with the director of a Nova series on human evolution (it looks like it’s available online here). He mentioned another interesting impact on human evolution: The weather. Apparently, whenever the weather changed dramatically, human evolution took a few leaps.

  6. Thanks, Jason, for your review of the review!

    I am not quite sure if I follow your critique of interactionism, which possibly might be because I am very excited about the systems approach, which is a form of interactionism. As I understand it, in the case of language, interactionism does not suggest that we are predisposed to learn a certain language but rather that the language we learn depends on our genetic ability to learn a language and what country we happen to be living in, who is talking to us etc. You are right, though, that the interesting question is not whether genes and the environment impact our linguistic expressions but how and to what extend. Systems theory, though, does not propose that language = genes + environment where we simply have to find the weights for each input variable but rather suggests a more complex interaction, that is, the genetic influence depends on the environment, which again depends on the genes (the environment wouldn’t matter if we didn’t have a predisposition to learn, for example, but rather came with an innate ability to speak French, say). Overall, I am afraid that human behavior is way more complicated than approaches such as those suggested in EP capture. Actually, that is probably true of most mammals, maybe even all animals…

    A book on the language development that was mentioned either by de Waal or Panksepp is by Terrence W. Deacon, a neuroscientist, called The Symbolic Species: The Co-evolution of Language and the Brain (here’s a review). I have not read it (and probably won’t since it’s over 400 pages and takes me away from the topics I want to research) but I thought I’d mention it as an alternative approach to language development, an approach that – at least based on the title and my rather cursory glance at the book – seems to incorporate more than genetic influences.

    I am not familiar with Blackburn’s other work but you might want to snoop around his webpage. From the book covers there, it looks like he’s influenced by David Hume’s philosophy.

  7. I read the article that you provided the link to. It was indeed a provocative and well written review of Steven Pinker’s book (although I think it’s better to read the book first before the reviews). Blackburn makes some excellent points about both the accomplishments and shortcomings of Pinker’s book in particular and his style of writing in general. I’m currently reading Pinker’s book, How the mind Words, and while I thoroughly enjoy his charmingly witty and erudite writing, he seems to present his arguments as a bit more rational and unbiased than they really are. Put more bluntly, although he claims that the nature/nurture debate is a false dichotomy, he seems to more or less favour the nature side and, to use Blackburn’s term, “demonizies,” the nurture side .

    I do, however, agree with one of Pinker’s points (which Blackburn did not address, surprisingly) which is that interactionism (the belief that behaviour is the result of the reciprical interaction between genes and the envioronment) is as equally facile as the nature/nurture dichotomy. Pinker uses language to exemplify the flaws of interactionism. According to this theory, both genes and the environment create behaviour, and it is the unique interaction of the these two factors that accounts for the wide range of variability among people’s behaviour. But in the case of which language we learn, this sort of logic would imply that some people are “predisposed” to learn french, while others English. In other words, suggesting that some traits are more (or in some cases, completely) genetic than enviormental, and vice versa. Interactionism is a platitudinal theory-that is, it states the obvious. Of course behaviour is shaped by both genes and the environment. The pressing question is to what extent is a particular behaviour influenced by these factors. Pinker is merely arguing that some traits are more heritable than others (e.g., intelligence), but somehow critics perceive this as evidence that Pinker disregards the importance of the environment, which is not invariably the case.

    Anyway, thanks for the link and if you have anymore articles, or know of any books, written by Blackburn I would greatly appreciate it if you would provide them for me.

    Oh! And here is the name of a book you might enjoy written by the scholar Kenan Malik- “Man, Beast, and Zombie”. The theme of the book is what science can and cannot tell us about human nature- it sounds interesting!

  8. I discovered an interesting critical review of Pinker’s book here. Since I finally started reading the book about systems theory, I can say that Pinker’s attempt to incorporate nurture into his nature picture is decidedly not overcoming the nature/nurture dichotomy but merely acknowledging that there could be other – minor! – influences in addition to genes. Simon Blackburn takes this on in his review. While Pinker realizes that we have to overcome the dichotomy, the EP approach is unsatisfactory because it ignores interaction and gives primary causal relevance to one side: Nature (in the form of genes).

  9. Justin: Thank you for the literature recommendations! I added hyperlinks to your comment to make the authors easier to find…

    I think in a lot of ways, your comment points to some of the troubling things with EP: Evolutionary psychologists seem to be enamored with the nature/nurture divide. And they tend to fall onto the nature side. That is particularly clear in a conversation that Steven Pinker had with Elizabeth Spelke had. As long as we have evidence that children are reared differently depending on gender, we cannot exclude nurture as an important variable in the equation. Please note that this does not mean that gender is socially constructed. Both nature and nurture have to be considered. We cannot dismiss either, like you are (almost) doing. I think because EP largely ignores or downplays the impact of the environment (broadly construed, not just limited to the parents, for example, but also including peers), EP always has the whiff of what Alan called “support of the status quo.”

    As I mentioned, Anne Fausto-Sterling identifies seven different systems that impact bone development. If we really want to understand if there is a difference between gender or race in bone development, we better take all seven into account. She gives one environmental example: If a woman has to wear a burka, her exposure to sunlight will be rather limited. This is likely to influence her bone health…

  10. I’m curious, why bring up creationism? Did I suggest that I was some sort of religious fundamentalist?

    Actually, I don’t have much interest in which theory best supports what.

    I was merely pointing out that I’ve seen what appears to be evolutionary psychology-type arguments used in support of socially conservative positions (which makes it all the more ironic that you seem to suspect I’m some sort of conservative).

    And I think it’s an oversimplification to say that evolutionary psychologists or any other type of scientist is not concerned with morality. Questions of morality will both influence research and be drawn from its conclusions, regardless of what the scientists in question intend.

  11. Can’t add much to the discussion but your last point is fallacious: “Might I ask, Allan, what other theory do you know of that can explain the current organization of the brain into seperate, distinct areas with seperate, distinct functions? Creationism?”

    The fact that there is no current theory good enough to explain these matters to the fullest doesn’t make the first one to shed fragments of light true.

  12. Evolutionary pscyhologists are not concerned with the issue of “morality”- they do not conclude that by virtue of its existence, a behaviour is “good” or even necessary for that matter. Natural selection is puposeless- it does not attempt to create a perfectly “good”, morarly righteous organism. If you read my first comment you would know that not all traits are an evolved adaptation- some are by-products of other traits while others are caused by “random” genetic noise.

    SInce the mind is responible for all behaviour and is subject to the same laws of physics and chemistry as the body, natural selection is capable of shaping its formation. In fact, it is the only explanation available that accounts for the wide range of functions and abilities that the brain is able of effectively performing.

    Might I ask, Allan, what other theory do you know of that can explain the current organization of the brain into seperate, distinct areas with seperate, distinct functions? Creationism?

  13. I’ve seen some evolutionary psychology articles. They tend to go something like this:

    1. They look at a present behavior in humans, and conclude that this behavior is somehow good and/or necessary.

    2. They then attempt to figure out how evolutionary pressures could have produced this trait.

    Always seems to be rampant speculation in support of the status quo.

  14. Thank you! I very much enjoyed reading your article and would love to discuss issues related to EP, or any other psychological discipline for that matter.

    I would recommend Steven Pinker‘s book, “The Blank Slate: The Modern Denial of Human Nature“. Although it’s not an evolutionary psychology book per se, he covers many of the basic premises of the discipline and applies them to the evolution of the human mind. More importantly, though, he offers an insightful examination of why so many intellectuals and laypeople, from both sides of the political spectrum, are hostile towards the idea of a universal human nature. He then assures the readers that they need not fear that acknowledging the existence of a “human nature” will result in discrimination, inequality, determinism, or nihilism.

    Anything by David Buss, one of the leading experts and researchers on EP, is worth reading as well such as the “The murderer next door”.

    If you are interested in the “birth order effect” I would suggest reading the book “Born to rebel“, in which the author approaches the topic from an evolutionary perspective.

    As for the differences between male and female child rearing, you won’t find many evolutionary theories that place much emphasis on child rearing techniques- and rightly so. If you actually examine the extant research on different parenting styles it becomes apparent that they have, relative to other environmental influences such peers (i.e, non-shared environment), very little effect on a child’s personality development. The parenting style theory (authoritative vs. authoritarian etc.) is a gross over simplification of the complex dynamics and interactions that take place in the home between parents and children. Twin studies have demonstrated, repeatedly I might add, that adoptive children, regardless of their age of adoption, are more like their biological parents than their adoptive parents.

    Now of course a child’s upbringing has SOME influence on his or her development, especially in extreme cases where there is parental neglect or sexual/physical abuse. But fortunately such extreme cases are relatively rare. In, for a lack of a better term, “normal” households (where there is no violence or sexual abuse) the relationship between parenting styles and children’s personality can just as easily be explained by genetics as the environment- intelligent, assertive, well-mannered parents beget intelligent, assertive, well mannered children. All these traits have strong genetic components. This is not to say that the environment has NO influence on the child’s personality, but rather that certain aspects of the environment, specifically the non-shared (i.e., friends, unique experiences outside the home) have a stronger influence than other aspects, such as parenting styles.

    As for gender differences, socialization is not the magical all mighty force that left-wing intellectuals, particularly social constructivists, make it out to be. Certain gender differences, for example, are universal and cross cultural and have existed for as long as humans have documented history. They also are observed in non-state, hunter gather societies, where “society” (whatever that term entails today) has no influence on human behaviour. There are logical evolutionary explanations that have been, and continue to be, confirmed in the experimental setting that account for the universally observed differences between the sexes. Males have had a greater propensity to violence than females since our evolution in our ancestral past, which is long before violent video games and UFC were introduced to society.

  15. Thank you, Justin! This is great! I was hoping that the de Waal and Panksepp articles, which were written in the early-2000s, were outdated… So, I am glad you gave a good update. Also, if there are some readings you could recommend, please feel free to do so (if you include more than 3 links, the comment will end up in the spam filter but I can release it from there…).

    Regarding my claim that “EP ignores the interaction of lots of different factors.” This is based on my reading of Fausto-Sterling’s “Bare Bones” article (I’ve only read Part I so far). She identified seven different systems that impact bone development – from genes to exposure to the sun. It is good to know that EP is integrating the environmental influences but there are probably many more factors even that need to be considered, including, for example, difference between male and female child rearing, children with or without siblings, availability of parents etc.

  16. I think you have raised some very interesting points regarding the limitations inherent in the evolutionary psychology discipline, but I also feel that you have set up several straw man arguments. Most of the criticisms mentioned above are directed toward earlier evolutionary theories, which were developed when the discipline was still young. For example, evolutionary psychologists today (at least the ones I read or have spoken to) do not believe that ALL traits have a function-such simplistic reasoning is called “naive darwinism”.

    You are correct in that several traits are, to use the correct evolutionary term, “by products” of (that is, they serve no function but are simply associated with other) evolved traits that do have an adaptive function. Very few evolutionary psychologists, if any, believe that rape is an evolved adaptation or that there is a “rape gene”. On the contrary, most subscribe to the theory that rape is a by product of other male evolved psychological mechanisms, such as a male’s desire for sexual variety, sexual over-perception bias (inferring sexual interest on behalf of a female when she isn’t), and use of violence to achieve goals, all of which have been empirically validated. The original book published on the topic was written because the authors were dissatisfied with the prevailing notion, popularized by feminists, that rape had nothing to do with sex, but was rather males attempt to oppress women. While this may be true in some instances, the latter theory had absolutely no empirical support whatsoever, but because it was postulated by feminists, most scholars chose not to question it scientifically, lest they be accused of being a sexist, much like the evolutionary psychologists who published the aforementioned book were (even though they started the book off by stating how abhorrent the crime rape was and how they hoped to completely eradicate it).

    EP theories do not implicate genes into their propositions- genes merely code for proteins which are the building blocks of cells, such as the neurons in the brain. Behaviour is far too complex for there to be one gene that is responsible for its existence. Moreover, there isn’t a “one-to-one” ratio for genes and behaviour, despite the illusion armchair critics create. Genes activate/deactivate other genes, which activate/deactivate other genes, all of which being subject to other factors, both internal and external. Evo psychologists focus specifically on observable and measurable behaviour, not genes. The basic premise of the EP discipline is that the mind is composed of several Evolved psychological mechanisms, or EPM’s, each designed (that is, shaped by natural selection) to solve specific adaptive problems. For example, the fusiform face area in the temporal lobe of the brain is responsible for processing and recognizing faces, the evolutionary benefit of which being fairly obvious.

    Today, EP is a multidisciplinary field, drawing from a multitude of disciplines, such as neuroscience, behavioural economics, social psychology, psychopathology, ethology, and primatology, to name but a few.

    “EP ignores the interaction of lots of different factors.”

    I’m not sure what gave you, or whoever was quoted saying that, the impression that EP ignores the interaction of several factors (I’m presuming she/he was referring to environmental factors?) Allow me to provide an example.

    Humans have an innate capacity to acquire and speak language. There are regions in the human brain that, during the prenatal developmental of the brain, are specifically organized and designed to process information related to language (words, syllables etc.). There are likely several genes that are responsible for the specialization of these areas in the brain, the unique combination of which being favoured by natural selection. The language we learn, however, depends entirely on our environment. If I live in Canada, which I do, I will most likely learn English or French. If I live in china I will most likely learn Mandarin and so and so forth. EPM’s (such as the one for language) process environmental input, operate by some algorithmic principle or rule (such as a “if then” or, in the case of language, syntax), and produce output such as behaviour (e.g., language) or a physiological response. The ability to learn language is universal- all, for a lack of a better term, “normal” humans have it. But the language we learn is dependent upon the environment.

    There are countless examples of other evolutionary theories that account for the bidirectional interaction between “genes” and the “environment”.

    So while your criticisms of EP as a discipline are valid in one way they are invalid in another. EP is constantly revising and changing its theories to accommodate for new evidence or to respond to valid criticisms.

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