Evolutionary Psychology, Jerry Coyne, Robert Kurzban And The So-Called Creationism Of The Mind

Massimo Pigliucci, 08/19/13

Time to take a break from philosophy of mind and get back to evolutionary psychology. The occasion originates from a recent post by evo psych researcher Robert Kurzban, on what he calls "creationism of the mind." There Kurzban excoriates our good old friend PZ Myers for some apparently silly criticisms he leveled at the field. Kurzban goes on commending Jerry Coyne for having recently seen the light, becoming a supporter of the field.

Contra to what some of my seasoned readers may expect, this is going to be neither a defense of PZ, nor an attack on Coyne. But I doubt Kurzban is going to like it anyway (about Jerry, I'm not taking bets).

Let's start with Kurzban's criticism of Myers, whom he tags with the obviously disdainful label of creationist of the mind. According to Kurzban, the latter is someone who subscribes

"to the view that the theory of evolution by natural selection ought to be used to inform the study of the traits and behaviors of every living thing on the planet except the bits of the human mind that cause behavior, especially social behavior."

I'm pretty sure no evolutionary biologist actually subscribes to this rather strawmanly view, including PZ, but let's proceed. Kurzban further characterizes this brand new type of "creationists" thusly:

"Like creationists full stop, creationists of the mind take their positions for reasons other than looking at the relevant evidence. This is clear from the emotion that pervades their remarks about the discipline."

Uhm, ok, though it is worth noting that this bit of rhetoric comes from someone who has by this point indulged in a pretty emotional characterization of his own opponents. [Note: I've got nothing against being emotional; to me it means one gives a damn. But you ought not to belittle your opponents for the same kind of behavior you yourself indulge in.]

What exactly did Myers say that so railed Kurzban? Apparently he stated that evolutionary biologists assume a one-to-one causal mapping of genes to behavior, proceeding to dismiss the field on the grounds that such an assumption is in fact ridiculously simplistic (it is). Well, if PZ did say that, he was also attacking a straw man. But the problem of genotype-phenotype mapping is, in fact, a rather big one for evopsych researchers, more so than for pretty much any other evolutionary biologist, because such mapping (i.e., the details of how phenotypes are causally related to genotypes) is made much more complex in humans by the existence of an enormous amount of behavioral plasticity, much of which is induced by a pesky little thing called culture, and all of which makes it pretty difficult (though not necessarily impossible) to test adaptive hypotheses about modern human behavior.

After having dismissed Myers, Kurzban moves on to some good news for evopsych: Jerry Coyne's alleged "conversion" to the field:

"Jerry Coyne’s conversion I think serves as a powerful example. His journey from staunch critic to defender of the discipline illustrates that smart people who know a lot about biology can be persuaded. Some of the field’s critics might be induced to read the primary literature, as Coyne did. More deeply, Coyne’s public change of heart, I think, will make it easier for others to say they were wrong."

(Note the use of religiously inspired terminology, such as "conversion" and "journey.")

But did Jerry change his position so dramatically? I went and checked what he actually wrote, and it doesn't sound at all like what Kurzban so enthusiastically described. Jerry confirms his (harsh) criticism of evopsych researchers like Randy Thornhill and Craig Palmer (them of "rape is an adaptive strategy" fame), as well as of much of "pop" evopsych (citing as one of the most ridiculous recent examples David Brooks' latest book - essentially a Republican fantasy of how things are and therefore ought to be in the world).

Nonetheless, Coyne continues, the field is, ahem, evolving, and getting better. There are some serious researchers who actually pay attention to the testability of their hypotheses, and who try to be careful about what they say when they write for the public. I don't know many critics - either within biology or in philosophy of science - who would disagree with that kind of cautious assessment. When Jonathan Kaplan and I wrote about evopsych in our Making Sense of Evolution we were careful to draw exactly the same distinctions that Jerry draws. I know there are misguided postmodernists out there who reject evopsych no matter what, but most thoughtful commentators have never done that, just like current critics of the excesses of neuroscience do not thereby dismiss it as phrenology.

That said, I still don't think Jerry's criticism of evopsych goes far enough, for one very important - but also, I would think, very obvious - reason:

human beings really do present special challenges when it comes to the scientific study of their behavior, especially of the evolution of that behavior.

To get us started, let's look at some of the entries in Jerry's list of recent successes (or at least examples of progress) in evopsych. Some are obvious and hard to dispute:

incest avoidance, innate fear of dangerous animals, parent-offspring conflicts, and the like.

As Kaplan and I (and plenty of others) have pointed out, these are the areas where evopsych is at its strongest because the target behaviors are common among mammals, or at least primates. Which means that phylogenetic comparative analyses - one of the best hypothesis testing tools at the disposal of evolutionary biologists - work well.

Other examples are a bit odd. Jerry mentions, for instance, the evolution of sexual dimorphism (differences in size between male and female) and the evolution of concealed ovulation in human females. These are actually morphological, not behavioral traits, though they certainly influence behavior (and perhaps have been historically influenced by behavior). One needs to be careful about not unduly expanding the domain of evopsych to include every human trait, or it becomes too easy to claim success. (For instance: yeah, human females evolved larger breasts than men because they nurse their babies. I doubt even a postmodernist would try to culturally relativize that one!)

Jerry also mentions traits that are variable within the human species (as opposed to the classical focus of evopsych, human universals), for instance offspring numbers across societies, or physical and physiological differences among ethnic groups (though, again, why would the latter count as behavior is a bit puzzling). Kaplan and I also highlighted this area (systematic variation within Homo sapiens) as potentially fruitful for evopsych, though caution needs to be exercised because some of these traits (e.g., offspring number) could vary at least in part as a result of cultural forces, not genetic evolution (just think of the differences between, say, some fundamentalist religious groups and many mainstream ones: in societies where the former are in significant numbers the birthrate will be much higher than in societies where religious fundamentalism is numerically insignificant, but I would guess that culture, rather than genetics, is doing much of the work here).

Jerry also counts as a success for evopsych research on gene-culture co-evolution, as in the famous case of lactose intolerance. Which is odd, because that approach is usually seen as significantly distinct from evopsych (it's based on the extension of standard population genetics models to cultural evolution), and at any rate has had somewhat limited success (there aren't that many documented cases around, other than the oft-cited lactose intolerance).

Things become seriously iffy with yet another group of examples advanced by Jerry as positive entries in the evopsych column:

the evolution of language and the evolution of morality.

Steven Pinker's interesting speculations aside, we really don't have much of a hold on the evolution of language, for the simple reason that it is a classical worst case scenario for evopsych: it is unique to humans (yes, yes, other animals communicate, but language is a whole different beast) and not really variable within humans - except for pathologies - which means that comparative phylogenetic studies are out; so, of course, is the fossil record (except insofar that tells us when we evolved the anatomy necessary for language); and, needless to say, we have no access to direct measurements of relevant selective pressures. Yes, something can be learned by the study of the (very complex) genetics underlying language abilities, but it is hard to see how one can significantly move away from the sort of "just-so" stories for which evopsych is infamous. (If these stories are instead presented as untested but reasonable scenarios, then it's a different matter.)

As for morality, I am the first to agree that Frans de Waal-type studies with other primates provide the basis for interesting speculations on how it evolved, but let's remember that his comparative studies are based on an extremely reduced number of species, that these species are pretty distantly related to us, and that they show very significant differences among themselves in terms of prosocial and pre-moral behavior. Not to mention that human morality is exceedingly more complicated than any animal equivalent because, you guessed it, of cultural evolution.

Which brings me to the crucial point where I disagree with Jerry about evopsych, in this case (which is unusual, believe me) in the sense that I am more conservative than he is. As Jerry puts it in his post:

"My position has always been that good evolutionary psychology should meet the evidentiary standards of papers on the evolutionary significance of behavior in other animals ... Those who dismiss evolutionary psychology on the grounds that it’s mere 'storytelling' ... if they are to be consistent, they must also dismiss any studies of the evolutionary basis of animal behavior."

Well, no, that's really moving the bar too low. Sure, evopsych research has to meet at the very least the standards of research on animal behavior (and believe me, a number of evopsych studies don't, though some certainly do). But human beings are far more complex and flexible (the technical term is plastic) in their behavior, and far less beholden to their genetic leash, than any other species on the planet, largely of course because of the power of cultural evolution. That means that evopsych researchers need to be much more careful in their studies than animal behaviorists, for precisely the same reasons that research psychologists get a lot more headaches while carrying out their work than their colleagues studying mice or fruit flies.

So, I agree with Jerry that it is silly to reject evopsych outright. It is a borderline field that can easily produce crap as well as good stuff. Therefor, criticism from the outside is vital in keeping evopsych tilting away from the former and increasingly toward the latter. But a rejection of certain conclusions alleged by evopsych does not at all require an equal rejection of animal behavior research. The standards ought to be higher.

Originally appear on Rationally Speaking, August 9, 2013

http://www.science20.com/rationally_speaking/evolutionary_psychology_jerry_coyne_robert_kurzban_and_socalled_creationism_mind-118195

Why Evolutionary Psychology Pisses You Off (And Why Maybe It Shouldn't)

Michael W. Taft, 03/02/12

If you want to irritate a lot of people at once, write an article about evolutionary psychology. Publishing such an article will invariably provoke a firestorm of denunciations and criticisms. Given the vehemence of these attacks, you couldn’t be blamed for thinking that the scientific basis for evolutionary psychology (or “evpsy” as it is sometimes abbreviated) was akin to tarot cards or bloodletting. Yet the basic premise of evpsy -- that some aspects of the human brain and behavior were subject to evolutionary pressures -- seems to be scientifically sound.

So what is it about this subject that makes it a napalm bomb for the inciting of flame wars? Below, I offer five things about evolutionary psychology that piss off scientists, feminists, policy wonks, and the rest of us, and explain why maybe they shouldn't.

1. It's obsessed with sex.

If you've been irritated by an evo psych piece lately, it probably has something to do with S-E-X. The media knows that stories about sexuality sell, and so is constantly pushing sex-centric evpsy articles of questionable scientific value. Take this recent example, discussing a study that supposedly explains why men fall asleep after sex. Hint: it's because they don't want to talk about commitment. No modern cultural issues posing as science there! Many evolutionary psychological studies reinforce modern gender stereotypes of men as horny, youth-fixated cads and women as sneaky, duplicitous gold-diggers, pissing off feminists and decent dudes while giving fodder to the worst of the pick-up artists.

To be fair, sexual selection is obviously important to evolution, and it makes sense that those interested in this field would be interested in what makes us select certain mates. Studies of human sexuality can be quite interesting and well-done, such as a 2008 study noting that women were more attracted to men who played team sports than those who played solo or non-athletes, likely due to team sports' reinforcing pro-social behavior. Still, I personally would love to see more studies like this one or this one, dealing with some of the subtle (if less sexy) intricacies of why we are the way we are.

2. It's bleak and deterministic.

Evolutionary psychology argues for a world in which our lives are governed by brain modules selected over millennia by evolution, so you can forget about free will. People tend to find it a bummer, as well as existentially threatening. As many evpsy critics argue, it also could also jeopardize public policy decisions intended to make us act better toward one another. If we’re all just “hardwired by evolution” to do the stupid stuff we do, like evpsy proponents suggest, then sociopolitical change is futile, right? Not exactly. For one, recent history has shown that, despite our nasty tendencies, overall we have become less prejudiced as a society. No, we don't have complete control over our own thoughts, but that doesn't mean we are doomed, tragic robots. Millennia of evolution have shaped us to be incredibly successful and adaptive organisms.

Humans live on every continent, thriving in areas far beyond the African savanna from which we originally came. Just because our minds were shaped in the past doesn't mean that we're predestined, but instead that we are destined to succeed.

3. It's just-so stories.

This insult comes straight out of Kipling, calling out evolutionary psychology for providing neat fables rather than hard science. Its hypotheses are untestable, inferred "just-so stories" whose only logic is internal. Since we can't go back in time and directly observe our hunter-gatherer ancestors, there is necessarily a creative element to evpsy reasoning. Still, I have to groan when I read about the infamous study "proving" that girls like pink because they need to be better at hunting for berries. The preference for pink as the color for girls was a twentieth century innovation, and it’s bad science like this makes evolutionary psychologists sound like caveman storytellers. This doesn’t mean that all of evo psych is not beyond rescue, however. Last year, an interdisciplinary group called for a reassessment of the principles of evolutionary psychology, proposing that it take advantage of breakthroughs in other areas of study and integrate with them so that it might gain "a rich source of hypotheses concerning the human mind, and could exploit novel methods from a variety of adjacent research fields."

Evolutionary psychology may be about to undergo some radical changes for the better.

4. It justifies bad behavior.

This combines #1 and #2 above, and adds in a touch more nasty. Because evolutionary psychology offers possible explanations for sexism, racism, homophobia, violence, and more, it can be seen as justifying or excusing bad behavior. Perhaps the ultimate expression of this has been made by Satoshi Kanazawa, who writes articles with titles like "Are All Women Essentially Prostitutes?", "Beautiful People Really ARE More Intelligent," or even "Why Are Black Women Less Physically Attractive Than Other Women?" The outrage he has provoked has led him to be denounced by his peers in the field.

But apart from rogues like Kanazawa, evolutionary psychologists who delve into these darker issues are (in general) not trying to justify them, just to explain why they might occur. Explaining something is not the same as excusing it. Human nature probably exists, and it's certainly not all sunshine and rainbows. However, new research continually finds evidence that, as much as we might have a predisposition for prejudice and violence, we're also hardwired by evolution to be empathetic and altruistic beings. Humanity is complex, neither good nor evil, but we can strive to be good, and part of improving the world is not ignoring the bad.

5. It's stuck.

Combined with recent advances in neuroscience, evolutionary psychology leaves us feeling almost as if we're nothing more than glorified monkeys, programmed by evolution. This threatens our ego big-time, since the ego wants to be in charge. However, research continually challenges some of the long-held ideas of evolutionary psychology, demonstrating that many adaptations are quite recent, and that our minds are still changing. We might be hardwired monkeys, but we are still in motion.

Evolution isn't just in the past. It's happening right now, as you read this in the modern environment. Instead of a harsh natural environment selecting for the most robust fighters or the sexiest mates, it’s our society that is putting on the pressure. In his recent book The Better Angels of Our Nature, evolutionary psychologist Steven Pinker shows just how much violence, sexism, racism, and other forms of hate have declined over the ages, in part because our society no longer accepts certain impulses once considered natural and normal. We are developing into gentler beings, despite and because of our nature.

Evolutionary psychology could have a lot to teach us, especially if it can take advantage of new discoveries in neuroscience and evolutionary biology. It needs to grow in scope and tackle things outside of the small box of the "environment of evolutionary adaptedness," since it's become evident that humans didn't evolve entirely in one specific time and space. An updated, more rigorous, less sensational form evolutionary psychology has the potential to answer not only where we come from, but where we are going.

http://www.science20.com/michael_taft/why_evolutionary_psychology_pisses_you_and_why_maybe_it_shouldnt-87622

What's Wrong With Evolutionary Psychology?

Gerhard Adam, 08/02/11

With several articles recently appearing that were based on various aspects of evolutionary psychology, I thought it would be worth taking a closer look.

One of the ironies in examining evolutionary psychology is how many stories we can make up for ourselves without a shred of conclusive evidence, beyond simply sounding plausible. This doesn't mean that they may not be true, but they certainly can't be considered scientific. I thought it would be interesting to examine several points regarding evolutionary psychology before going further:

It is not an area of study, like vision, reasoning, or social behavior. It is a way of thinking about psychology that can be applied to any topic within it. (1)

While this sounds like a very reasonable assessment, it is almost immediately ignored by framing everything that follows as a specific point of study. Five principles are then presented that frame the basis for evolutionary psychology.

Principle 1. The brain is a physical system. It functions as a computer. Its circuits are designed to generate behavior that is appropriate to your environmental circumstances.

The big problem here is in reducing the brain to a computer, which it isn't. While it might be a useful analogy within a very narrow context, it is simply foolish to define biology in terms of recent human technological developments (i.e. computers, machines, etc.). This is simply unacceptable, in the same way that electrons are not like billiard balls, neither is the brain a computer. In truth, there is nothing in the operation of a computer that could find an accurate comparison to the brain's neurobiology (unless one is content to make the comparison simply because signals may be sent electrically). However, by that logic, a television, telephone, and radio are all computers too.

Organisms that don't move, don't have brains. Trees don't have brains, bushes don't have brains, flowers don't have brains.

This kind of misunderstanding is simply ridiculous. One has to wonder what kind of brain bacteria possess. Let's also not forget the mimosa plant (Mimosa piduca).

Principle 2. Our neural circuits were designed by natural selection to solve problems that our ancestors faced during our species' evolutionary history.

In this case, the problem occurs with words like "designed", because that already indicates a fundamental failure to understand evolution and natural selection. In the first place, why presume that the brain evolved to "solve problems"? There are organisms that don't even have nervous systems that are capable of that function. More importantly, what problems are so unique to humans that they should be the only species to have "evolved" such a brain? Considering the simple reality that there are no particularly unique problems that humans solve, then we must conclude that this is an insufficient reason to explain the existence of the human brain. It is a classic error in assuming that modern day biological structures are necessarily adaptive. After all, it is equally plausible to assume that brain development diverged due to a random mutation, and that it's subsequent benefits moved humans down a different evolutionary path.

For you, that pile of dung is "disgusting".

Once again, an interesting story, but simply not true. Dung is often used to assess an animal that someone is tracking, and certainly carries vastly different interpretations depending on the animal of origin. In fact, given the cultures which still use dung for fires and fertilizers, this assertion is clearly a product of a modern urban mindset rather than anything to do with human evolution or psychology. This is so basic, that one can't help but marvel at how myopic this "understanding" of human psychology is.

But what did the actual designer of the human brain do, and why? Why do we find fruit sweet and dung disgusting?

This kind of statement is simply embarrassing.

Principle 3. Consciousness is just the tip of the iceberg; most of what goes on in your mind is hidden from you. As a result, your conscious experience can mislead you into thinking that our circuitry is simpler that it really is. Most problems that you experience as easy to solve are very difficult to solve -- they require very complicated neural circuitry

This certainly appears to be true, but I don't see why it's a principle of anything. Once again, it seems much more appropriate to turn this around and argue that the "mind" exists in numerous organisms and it is only recently in human development that consciousness emerged as a trait. I'm not clear why an individual's perception of their personal brain circuitry is of any consequence as a "principle".

...so complex, in fact, that no computer programmer has yet been able to create a robot that can see the way we do.

Doing what comes "naturally", effortlessly, or automatically is rarely simple from an engineering point of view.

It seems like the point is to warn against over-simplifying and yet that's precisely what occurs when words like "engineering" are used to describe a phenomenon which has never been successfully engineered.

Principle 4. Different neural circuits are specialized for solving different adaptive problems.

Interesting idea, but where's the evidence for this? This requires a level of study that simply doesn't exist. In the first place, we have to demonstrate that there are specific psychological responses that are unique to particular adaptive problems. We then have to demonstrate that these behaviors are heritable and governed by neural circuits that fulfill no other more general purpose. This is exceedingly unlikely and the most likely explanation is that our brain is much more flexible than it is specialized to specific problems.

This isn't to say that there aren't specific capabilities that our brain has evolved for, but it is unlikely that they are unique to humans and instead will likely prevail throughout many other mammal's brains. So while we can certainly agree that there are visual or auditory centers in the brain, it is not at all clear that they are uniquely human, nor does it explain anything about how the brain actually maps such sensory data into the context of a "mind" or consciousness.

For example, we all have neural circuitry designed to choose nutritious food on the basis of taste and smell -- circuitry that governs our food choice. But imagine a woman who used this same neural circuitry to choose a mate.

It is also difficult to determine whether these principles are being written as serious definitions or whether they are intended to entertain school children. To suggest that our brain is operating substantively different in choosing food versus choosing mates, indicates such a fundamental misunderstanding about neurobiology, it is mystifying.

Principle 5. Our modern skulls house a stone age mind.

This makes little sense, since it arbitrarily separates "mind" from "brain". After all, this assertion basically argues that evolution has stopped or is unresponsive to human needs. This claim flies in the face of the actual evidence which indicates that humans are a phenomenally adept species and are extremely well adapted to their environment. In fact, the fallacy appears to be based on the notion that somehow we shouldn't experience any challenges, but that rather we should have evolved so that anything we engage in is "effortless". However, it should be obvious that we cannot behave or perform in ways that our brain can't handle. So, while we may personally believe that it isn't as easy as we might wish, there is no evidence to suggest that we aren't adapted to everything we do.

This becomes especially relevant when we want to argue about how our culture has changed us and somehow our behaviors have difficulty keeping pace with those changes. Where is the evidence for this? Is this being assumed simply because of the perception of increased psychological disorders or stresses? Once again, what evidence do we have that such disorders haven't always been present?

Generation after generation, for 10 million years, natural selection slowly sculpted the human brain, favoring circuitry that was good at solving the day-to-day problems of our hunter-gatherer ancestors -- problems like finding mates, hunting animals, gathering plant foods, negotiating with friends, defending ourselves against aggression, raising children, choosing a good habitat, and so on. Those whose circuits were better designed for solving these problems left more children, and we are descended from them.

This statement is simply stupid, because it presumes that we are the hapless victims of a natural selection process that simply can't keep up. It demonstrates a uniform failure to understand that natural selection does not "sculpt" nor "design", but simply ensures that an organism has the necessary traits to survive in the environment in which it exists. No matter how it is considered, the filter of natural selection doesn't only work sometimes. If a species survives (including humans) then it has passed the "selection test". If the point is to argue that our brain is maladaptive, then it requires a bit more than fantasy stories about how cavemen are believed to have lived. It is also curious that of all the attributes listed, virtually none of them are demonstrably "hard-wired". With this kind of basic misunderstanding, it's difficult to assign much credibility to Evolutionary Psychology claims.

After examining these principles and many other points regarding various debating points such as "nature vs nurture" it becomes clear that evolutionary psychology simply isn't ready for prime time, either as a discipline or even as a perspective. In fact, a strong argument can be made that when using evolutionary biology as a perspective in examining behavior there is a real risk of telling oneself convenient stories based on little more than conjecture or imaging what "things must've been like".

Without some insight that is nothing short of miraculous, there is no such thing as evolutionary psychology. So for those that want to insist otherwise, here's the criteria that must be met:

1. Demonstrate that the behavior is neurologically specific enough to be predicted.
2. Demonstrate that such behavior is heritable (Note: Learning, by itself, is not sufficient).
3. Demonstrate that such heritability actually is adaptive.

These requirements are quite difficult to meet for many aspects of biology, especially that of establishing that a trait is adaptive. However, to glibly toss off explanations based on some arbitrary notion about how early humans lived is simply idle speculation and nonsense.

Note:

(1)  All quotes and references come from the Center of Evolutionary Psychology, "The Evolutionary Psychology Primer"
http://www.psych.ucsb.edu/research/cep/primer.html

http://www.science20.com/gerhard_adam/whats_wrong_evolutionary_psychology-81398

Should Evolutionary Psychology Evolve?

未署名, 07/22/11

Evolutionary psychology is a field that examines human psychological traits through evolutionary glasses. Most human psychological traits are considered adaptations, the functional products of natural or sexual selection. This is tidily summarized in a quote from Cosmides and Tooby, two of the founders of the field:

Our modern skulls house a Stone Age mind.

The field, however, is quite controversial. Proponents tend to explain every aspect of the human psyche through evolutionary adaptation, whereas opponents often express the criticism that these are ‘just-so stories’. Between these two positions, of course, many more moderate ones are possible.

Now, a publication in PLoS Biology argues that evolutionary psychology itself should adapt to the knowledge gained from new findings in a variety of fields, ranging from evolutionary biology to cognitive neuroscience. Firstly, the authors identify the four basic tenets of evolutionary psychology.

·        The environment of evolutionary adaptedness (or EEA). Basically, the idea that our modern psychological mechanisms have evolved in response to stable features in the environment of our ancestors (assumed to be the African Pleistocene savanna).

·        Gradualism. According to evolutionary psychologists, our minds are built from co-adapted gene complexes that are unable to respond quickly to changes.

·        Massive modularity. Since different adaptive problems require different solutions, the mind is assumed to consist out of different modules, eahc dealing with a different problem.

·        Universal human nature. The evolved computational programmes in our brains produce a universal human nature.

Then, the authors continue with a reassessment of these four basic tenets in light of new evidence. For example, they quote evidence that the EEA wasn’t nearly as stable as previously thought, but rather a very variable environment, challenging the notion that our modern psychological mechanisms were formed in a stable EEA.

Continuing, evidence is presented that there has been substantial genetic change in human beings, even in the last 50,000 years. There is even evidence suggesting that recent human evolution has been affected by human-induced changes in the environment (such as diet, or living conditions). These rapid changes are a challenge for the gradualism, as interpreted by evolutionary psychologists.

To challenge the idea of universalism, the authors cite evidence stressing the ‘malleability’ of the human brain, meaning that experience affects neural circuitry and gene expression in that remarkably complex center of the nervous system. The influence of development is equally stressed, as is the view that the human brain is built through continuous interplay between the individual and the environment. Gene-culture coevolution is also mentioned, signifying that cultural practices could have influenced selection pressures on the human brain.

Finally, massive modularity is questioned, through the existence of domain-general mechanisms (such as associative learning, which is fairly widespread in the animal kingdom), and through the broad involvement of diverse neural structures in many psychological processes.

After this reassessment, the authors offer some advice on how evolutionary psychology could adapt to all this new evidence.

·        The evolution of a character can be evaluated through the construction and testing of population genetic models, estimating and measuring the responses to selection, exploring the covariation of phenotypic traits or genetic variation with putative selective agents, and so forth, much as evolutionary biologists do.

·        The new evidence suggests that human beings experience less adaptive lag (being adapted to an environment in the past, and not to the present one) than previously supposed. An examination of the relationship between evolved psychological mechanisms and reproductive success in modern environments might help in elucidating this. Analyses, optimality models and gene-culture coevolutionary models could also be used to research whether or not current human behavior is adaptive in present-day environments.

·        The hypotheses of how the brain works can be compared to (cross-cultural) neuroscientific research, to see if this supports the hypotheses. Also, the genetic influence on brain formation and functioning could be involved here.

·        Through the use of developmental genetics and psychology, the unlearned roots of cognition might be detected. This could also help in understanding how culturally and individually dependent concepts emerge.

The authors conclude:

None of the aforementioned scientific developments render evolutionary psychology unfeasible; they merely require that EP should change its daily practice. The key concepts of EP have led to a series of widely held assumptions (e.g., that human behaviour is unlikely to be adaptive in modern environments, that cognition is domain-specific, that there is a universal human nature), which with the benefit of hindsight we now know to be questionable. A modern EP would embrace a broader, more open, and multi-disciplinary theoretical framework, drawing on, rather than being isolated from, the full repertoire of knowledge and tools available in adjacent disciplines. Such a field would embrace the challenge of exploring empirically, for instance, to what extent human cognition is domain-general or domain specific, under what circumstances human behaviour is adaptive, how best to explain variation in human behaviour and cognition. The evidence from adjacent disciplines suggests that, if EP can reconsider its basic tenets, it will flourish as a scientific discipline.

Reference

Bolhuis, J.J.; Brown, G.R.; Richardson, R.C. and Laland, K. (2011). Darwin in Mind: New Opportunities for Evolutionary Psychology. PLoS Biology. 9(7): e1001109. doi:10.1371/journal.pbio.1001109. (Click here for the article)

http://www.science20.com/curious_cub/should_evolutionary_psychology_evolve-81112