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One debate in the philosophy of science is whether or not a scientific hypothesis should make testable predictions or merely explain only what it purports to explain. Should a scientific hypothesis H predict previously unknown facts of the matter or only explain an observation? Take, for example, evolutionary psychology (EP). Any EP hypothesis H can speculate on the so-called causes that led a trait to fixate in a biological population of organisms, but the claim that they can do more than that—that is, that they can generate successful predictions of previously unknown facts not used in the construction of the hypothesis—but that’s all they can do. The claim, therefore, that EP hypotheses are anything but just-so stories, is false.
Prediction and novel facts
For example, Einstein’s theory of general relativity predicted the bending of light, which was a novel prediction for the hypothesis (see pg 177-180 for predictions generated from Einstein’s theory). Fresnel’s wave theory of light predicted different infraction fringes to the prediction of the white spot—a spot which appears in a circular object’s shadow due to Fresnel diffraction (see Worrall, 1989). So Fresnel’s theory explained the diffraction and the diffraction then generated testable—and successful—novel predictions (see Magnus and Douglas, 2013). There is an example of succeful novel prediction. Ad hoc hypotheses are produced “for this” explanation—so the only evidence for the hypothesis is, for example, the existence of trait T. EP hypotheses attempt to explain the fixation of any trait T in humans, but all EP hypotheses do is explain—they generate no testable, novel predictions of previously unknown facts.
A defining feature of science and what it purports to do is to predict facts-of-the-matter which are yet to be known. John Beerbower (2016) explains this well in his book Limits of Science? (emphasis mine):
At this point, it seems appropriate to address explicitly one debate in the philosophy of science—that is, whether science can, or should try to, do more than predict consequences. One view that held considerable influence during the first half of the twentieth venture is called the predictivist thesis: that the purpose of science is to enable accurate predictions and that, in fact, science cannot actually achieve more than that. The test of an explanatory theory, therefore, is its success at prediction, at forecasting. This view need not be limited to actual predictions of future, yet to happen events; it can accommodate theories that are able to generate results that have already been observed or, if not observed, have already occurred. Of course, in such cases, care must be taken that the theory has not simply been retrofitted to the observations that have already been made—it must have some reach beyond the data used to construct the theory.
That a theory or hypothesis explains observations isn’t enough—it must generate successful predictions of novel facts. If it does not generate any novel facts-of-the-matter, then of what use is the hypothesis if it only weakly justifies the phenomenon in question? So now, what is a novel fact?
A novel fact is a fact that’s generated by hypothesis H that’s not used in the construction of the hypothesis. For example, Musgrave (1988) writes:
All of this depends, of course, on our being able to make good the intuitive distinction between prediction and novel prediction. Several competing accounts of when a prediction is a novel prediction for a theory have been produced. The one I favour, due to Elie Zahar and John Worral says that a predicted fact is a novel fact for a theory if it was not used to construct that theory — where a fact is used to construct a theory if it figures in the premises from which that theory was deduced.
Mayo (1991: 524; her emphasis) writes that a “novel fact [is] a newly discovered fact—one not known before used in testing.” So a fact is novel when it predicts a fact of the matter not used in the construction of the hypothesis—i.e., a future event. About novel predictions, Musgrave also writes that “It is only novel predictive success that is surprising, where an observed fact is novel for a theory when it was not used to construct it.” So hypothesis H entails evidence E; evidence E is not used in the construction of hypothesis H, therefore E is novel evidence for hypothesis H.
To philosopher of science Imre Lakatos, a progressive research program is one that generates novel facts, whereas a degenerating research program either fails to generate novel facts or the predictions made that were novel continue to be falsified, according to Musgrave in his article on Lakatos. We can put EP in the “degenerating research program, as no EP hypothesis generates any type of novel prediction—the only evidence for the trait is the existence of the trait.
The term “just-so stories” comes from Rudyard Kipling Just-so Stories for Little Children. Then Gould and Lewontin used the term for evolutionary hypotheses that can only explain and not predict future as-of-yet-known events. Law (2016) notes that just-so stories offer “little in the way of independent evidence to suggest that it is actually true.” Sterelny and Griffiths (1999: 61) state that just-so stories are “… an adaptive scenario, a hypothesis about what a trait’s selective history might have been and hence what its function may be.” Examples of just-so stories covered on this blog include: beards, FOXP2, cartels and Mesoamerican ritual sacrifice, Christian storytelling, just-so storytellers and their pet just-so stories, the slavery hypertension hypothesis, fear of snakes and spiders, and cold winter theory. Smith (2016: 278) has a helpful table showing ten different definitions and descriptions of just-so stories:
So the defining criterion for just-so stories is that there must be independent evidence to believe the proposed explanation for the existence of the trait. There must be independent reasons to believe a certain hypothesis, as the defining feature of a scientific hypothesis or theory is whether or not it can predict yet-to-happen events. Though, as Beerbower notes, we have to be careful that we do not retrofit the observations.
One can make an observation. Then they can work backward (what Richardson (2007) elicits is “reverse engineering”) and posit (speculate about) a good-sounding story (just-so storytelling) to explain this observation. Reverse engineering is “a process of figuring out the design of a mechanism on the basis of an analysis of the tasks it performs” (Buller, 2005: 92). Of course, the just-so storyteller can then create a story to explain the fixation of the trait in question. But that’s only (purportedly) the explanation of why the trait came to fixation for us to observe it today. There are no testable predictions of previously unknown facts. So it’s all storytelling—speculation.
The theory of natural selection is then deployed to attempt the explain the fixation of trait T in any population. It is true that a hypothesis is weakly corroborated by the existence of trait T, but what makes it a just-so story is the fact that there are no successful predictions of previously unknown facts,
When it comes to EP, one can say that the hypothesis “makes sense” and it “explains” why trait T still exists and went to fixation. However, the story only “makes sense” because there is no other way for it to be—if the story didn’t “make sense”, then the just-so storyteller wouldn’t be telling the story because it wouldn’t satisfy their aims of “proving” that a trait is an adaptation.
Smith (2016:277-278) notes 7 just-so story triggers:
1) proposing a theory-driven rather than a problem-driven explanation, 2) presenting an explanation for a change without providing a contrast for that change, 3) overlooking the limitations of evidence for distinguishing between alternative explanations (underdetermination), 4) assuming that current utility is the same as historical role, 5) misusing reverse engineering, 6) repurposing just-so stories as hypotheses rather than explanations, and 7) attempting to explain unique events that lack comparative data.
EP is most guilty of (3), (4), (5), (6), and (7). It is guilty of (3) in that it hardly ever posits other explanations for trait T, it’s always “adaptation”, as EP is an adaptationist paradigm. It is guilty of (4) perhaps the most. That trait T still exists and is useful for this today is not evidence that trait T was selected-for its use as we see it today. This then leads to (5) which is the misuse of reverse engineering. Just-so stories are ad hoc (“for this”) explanations and these types of explanations are ad hoc if there is no independent data for the hypothesis. Of course, it is guilty of (7) in that it attempts to explain, of course, unique events in human evolution. Many problems exist for evolutionary psychology (see for example Samuels, 1998; Lloyd, 1999; Prinz, 2006;), but the biggest problem is the ability of any hypothesis to generate testable, novel predictions. Smith (2016: 279) further writes that:
An important weakness in the use of narratives for scientific purposes is that the ending is known before the narrative is constructed. Merton pointed out that a “disarming characteristic” of ex post facto explanations is that they are always consistent with the observations because they are selected to be so.
Bo Winegard, in his defense of just-so storytelling, writes “that inference to the best explanation most accurately describes how science is (and ought to be) practiced. According to this description, scientists forward theories and hypotheses that are coherent, parsimonious, and fruitful.” However, as Smith (2016: 280-281) notes, that a hypothesis is “coherent”, “parsimonious” and “fruitful” (along with 11 more explanatory virtues of IBE, including depth, precision, consilience, and simplicity) is not sufficient to accept IBE—IBE is not a solution to the problems proposed by the just-so story critics as the slew of explanatory virtues do not lend evidence that T was an adaptation and thusly do not lend evidence that hypothesis H is true.
Simon (2018: 5) concludes that “(1) there is much rampant speculation in evolutionary psychology as to the reasons and the origin for certain traits being present in human beings, (2) there is circular reasoning as to a particular trait’s supposed advantage in adaptability in that a trait is chosen and reasoning works backward to subjectively “prove” its adaptive advantage, (3) the original classical theory is untestable, and most importantly, (4) there are serious doubts as to Natural Selection, i.e., selection through adaptive advantage, being the principal engine for evolution.” (1) is true since that’s all EP is—speculation. (2) is true in evolutionary psychologists notice trait T and that, since it survived today, there must be a function it performs for why natural selection “selected” the trait to propagate in species (though selection cannot select-for certain traits). (3) it is untestable in that we have no time machine to go back and watch how trait T evolved (this is where the storytelling narrative comes in: if only we had a good story to tell about the evolution of trait T). And finally, (4) is also true since natural selection is not a mechanism (see Fodor, 2008; Fodor and Piattelli-Palmarini, 2010).
EP exists in an attempt to explain so-called psychological adaptations humans have to the EEA (environment of evolutionary adaptiveness). So one looks at the current phenotype and then looks to the past in an attempt to construct a “story” which shows how a trait came to fixation. There are, furthermore, no hallmarks of adaptation. When one attempts to use selection theory to explain the fixation of trait T, they must wrestle with spandrels. Spandrels are heritable, can increase fitness, and they are selected as well—as the whole organism is selected. This also, of course, falls right back to Fodor’s (2008) argument against natural selection. Fodor (2008: 1) writes that the central claim of EP “is that heritable properties of psychological phenotypes are typically adaptations; which is to say that they are typically explained by their histories of selection.” But if “psychological phenotypes” cannot be selected, then the whole EP paradigm crumbles.
This is why EP is not scientific. It cannot make successful predictions of previously unknown facts not used in the construction of the hypothesis, it can only explain what it purports to explain. The claim, therefore, that EP hypotheses are anything but just-so stories is false. One can create good-sounding narratives for any type of trait. But that they “sound good” to the ear, and are “plausible” are not reasons to believe that the story told is true.
Are all hypotheses just-so stories? No. Since a just-so story is an ad hoc hypothesis and a hypothesis is ad hoc if it cannot be independently verified, then a hypothesis that makes predictions which can be independently verified are not just-so stories. There are hypotheses that generate no predictions, ad hoc hypotheses (where the only evidence to believe H is the existence of trait T), and hypotheses that generate novel predictions. EP is the second of these—the only evidence we have to believe H is true is that trait T exists. Independent evidence is a necessary condition of science—that is, the ability of a hypothesis to predict novel evidence is a necessary condition for science. That no EP hypothesis can generate a successful novel prediction is evidence that all EP hypotheses are just-so stories. So for the criticism to be refuted, one would have to name an EP hypothesis that is not a just-so story—that is, (1) name an EP hypothesis, (2) state the prediction, and then (3) state how the prediction follows from the hypothesis.
To be justified in believing hypothesis H in explaining how trait T became fixated in a population there must be independent evidence for this belief. The hypothesis must generate a novel fact which was previously unknown before the hypothesis was constructed. If the hypothesis cannot generate any predictions, or the predictions it makes are continuously falsified, then the hypothesis is to be rejected. No EP hypothesis can generate successful predictions of novel facts and so, the whole EP enterprise is a degenerative research program. The EP paradigm explains and accommodates, but no EP hypothesis generates independently confirmable evidence for any of its hypotheses. Therefore EP is not a scientific program and just-so stories are not scientific.
As a bearded man, this has to be one of my favorite just-so stories. In Descent of Man, Darwin spoke quite a bit about the beard, and the different races/ethnies and the distribution of beards in them. Darwin (1871: 581) wrote:
On the other hand, bearded races admire and greatly value their beards ; among the Anglo-Saxons every part of the body had a recognised value … [also writing on pg 603] … for we know that with savages, the men of the beardless races take infinite pains in eradicating every hair from their faces as something odious, whilst the men of the bearded races feel the greatest pride in their beards.
Any man who has grown a beard admires and greatly values their beard. Darwin noted that beards were scant in Asian and Native American populations, as well as in Africa.
“Darwin specifically cited the human beard as a response to sexual selection serving mate attraction.” [Psychology Today, Beauty and the Beard]
Now, going off of this, we have this just-so story.
Men with the best beards attracted the most mates. Men who attracted the most mates had the most children. Men who had the most children had the best beards therefore, “beard genes” were naturally selected and eventually became fixated in males.
This has to be my favorite just-so story.
The New Republic almost word-for-word states my just-so story provided above:
Over the millennia, the theory goes, beardedmen were more successful in procreation than their smoother competitors, and the human beardevolved into its present form.
With so many so-called adaptations and things serving as “mate attractors”, how can selection “know” which trait to “act on”? This shows the ridiculousness of the just-so storytellers main weapon: reverse engineering.
Reverse engineering is “the inference from function to cause” (Richardson, 2007: 51). So they take the function (beards are seen as attractive to women) and then infer the cause (men with the best, most attractive beards were selected by women and thus “beard genes” became fixated in males since the best beards were fitness signallers to women since they found them attractive). But there is a flaw with reverse engineering: when accounting for such “design” in nature, in terms of adaptation, it can lead to just-so storytelling. AKA ad hoc hypotheses that explain what they purport to explain and only what they purport to explain.
Reverse engineering uses the design feature (beards) then extrapolate backward to presume its function (men with beards were seen as more attractive and thus, ‘beard genes’ became fixated since that’s what women found attractive). Reverse engineering can be used to make any story sound coherent; they necessarily conform with the data. Indeed, as Smith (2016: 279; emphasis mine) writes:
An important weakness in the use of narratives for scientific purposes is that the ending is known before the narrative is constructed. Merton42 pointed out that a “disarming characteristic” of ex post facto explanations is that they are always consistent with the observations because they are selected to be so.
This is why it’s problematic to accept this type of storytelling: they are consistent with the observations because they are crafted that way, but there is no observation that would increase the probability of the hypothesis being true so it’s just storytelling. In lieu of a time machine, we cannot verify these types of stories.
So we notice that beards (obviously) exist. Then we work backward and infer the function from the already-known outcome (as seen above). We then create the story that they were seen as attractive to women, thus they have been selected by women since they make for a more attractive mate. That a hypothesis conforms with the observation is not evidence that the hypothesis in question is true.
Research exists that men with beards are seen as more formidable mates for long-term relationships (Dixson et al, 2016). Mcintosh et al (2017) reported that “Women preferred full beards over clean-shaven faces and masculinised over feminised faces.” However, there is data that men with beards are perceived as more dominant but are not seen as more attractive than clean-shaven faces (Muscarella and Cunningham, 1996; Neave and Shields, 2008) Though evidence for current adaptiveness is not evidence for evolutionary adaptiveness. The fact that X is adaptive today is not evidence that X was adaptive in the human OEE (original evolutionary environment). This again goes back to reverse engineering. Attempting to account for design in nature amounts to nothing but storytelling since the hypotheses are inherently ad hoc. Evolutionary functional analysis most definitely leads to just-so storytelling, and the story of how and why men have beards falls prey to this as well.
Men’s beards may be the result of women’s choice, as X may be the reason for Y, but without a way to independently verify the hypothesis in question, it is then a just-so story. No, showing that women find men with beards to be better long-term partners is not evidence that female choice in the OEE (or in any point in evolutionary history) is evidence for the claim that beards became fixated in males due to female choice—sexual selection.
The problem with adaptationist explanations is that other modes of evolution are disregarded (nevermind the fact that the supposed mode of adaptation is supposed to be natural selection for the specific fitness-enhancing trait which cannot occur since NS has no mind and there are no laws of selection for trait fixation; Fodor, 2008; Fodor and Piatteli-Palmarini, 2010; also see Replies to Our Critics) such as drift, mutation, and migration (see Gould and Lewontin, 1979; also see Simon, 2018 for other critiques of EP hypotheses, namely that they are not testable).
In sum, the story that beards were sexually selected-for by women due to X (no matter what X is, be it attractiveness, dominance, etc) is a just-so story. It cannot be independently verified. Yes, beards are seen as status symbols and there is a considerable amount of research on men’s beards and what women think they mean today, but, again, that X is adaptive today is not evidence that X was adaptive in an evolutionary context. Simplicity, coherence, and fruitfulness are no reasons to believe a hypothesis (Smith, 2016); the hypothesis must be independently testable but there is no way to test this hypothesis—or any other—that trait X (beards, in this case) moved to fixation in virtue of its effect on reproductive fitness, therefore it is a just-so story.
The four men in the title are, in my opinion, the biggest just-so storytellers in the “HBD” movement. These four men have written numerous journal articles and books pushing their just-so stories—making a career out of storytelling. We have Rudyard Kipling’s Just So Stories for Little Children, well Rushton, Lynn, Kanazawa, and Hart (RLKH) told Just-so Stories for Adults—like all EP is. Either way, RLKH have quite the following—those who would defend their just-so stories—and if you deny and question them, you’re “denying evolution” and are “no better than a creationist.” Well, too bad for them, rejecting just-so stories means nothing of the sort.
So even though humans as a species are incredibly K selected, some believe that some humans are more K selected than others. In other words, while some men have numerous sexual partners and father lots of illegitimate babies with different mothers, other men are more nerdy, and father very few children with only one woman, but they make sure those children are well parented and provided for.
When men first evolved in the warm hospitable tropics some 200,000 years ago, survival was relatively easy, so instead of natural selection (survival of the fittest), genetic fitness was determined by who could get the most women (sexual selection). As a result, men with the biggest muscles, highest testosterone, best social skills, most charisma and sexual abilities, were the most successful at passing on their genes. But as the ice age emerged and humans moved North, passing on genes became more about natural selection and less about sexual selection. What good is it to be a great pick up artist if you can’t survive the winter long enough to mate? (PumpkinPerson; Why women hate nerdy men)
When asked “why white women didn’t evolve to prefer nerds,” PumpkinPerson writes that “cold climate women evolved to be submissive so their preferences were prehistorically irrelevant.” More and more just-so stories. That’s all “HBD” is: a collection of just-so stories.
Sexual selection is a subset of “natural selection” but there is one important difference: humans have minds and thus, humans can *attempt to* “select-for” traits, but each trait is coextensive with an infinitude of traits which throws a wrench in the notion. There is no such thing as “natural selection (Fodor and Piatteli-Palmarini, 2010).
The above just-so story, personally, is one of my favorites, in the top ten, at least. This type of just-so story was popularized by Rushton and his r/K selection theory (read the rebuttal here; I also have many rebuttals of Anonymous Conservatives just-so stories, his attempted revival of Rushton’s storytelling). Africans, like PP claimed above, evolved in hotter, harsher environments, and so had to have more progeny in order to ensure reproductive success. On the other hand, when Man out of Africa, he encountered colder temperatures and, it is said, had to have fewer children in order to ensure that the children were looked after.
According to Richard Lynn, then, this migration into colder climates caused a decrease in colder climates due to a shift to “K strategy”, which then “selected-for” lower testosterone (Lynn, 1990). In Lynn (1990), he claims that differences in PCa (prostate cancer) are evidence for the claim that blacks have higher levels of testosterone than whites, which drives behavioral differences between the races. He then assumes that these differences have an evolutionary origin between the races, and that migrating into colder climates caused a decrease in testosterone in Europeans compared to Africans. However, one large mistake that Lynn (1990) makes is assuming that testosterone levels today have any bearing on testosterone levels thousands of years ago.
Claims that PCa are caused by higher levels of testosterone are ubiquitous in the “HBD” literature. But, as I have covered in the past, there is no reason to be scared of the hormone testosterone (read my most extensive review here); testosterone does not cause aggression and it does not cause PCa (Stattin et al, 2003).
One of the most oft-cited studies on the matter of T differences between blacks and whites is a small, highly methodologically/conceptually flawed study by Ross et al (1986). I have documented numerous flaws with the study.
So Lynn, in his 1990 just-so story shown above, claims that, due to colder temperatures, children would have needed more attention. Giving more attention would have meant having fewer children. This was done, he claims, through shifting to K strategy. So then, a decrease in testosterone was how to achieve this “K adaptation”, and achieving this “K adaptation” was through a reduction in T levels which subsequently, according to Lynn, brought “about a lowering of sexual drive and behaviour” (Lynn, 1990: 1205).
Note how Lynn’s claims in this paper *completely rest on* differences in prostate cancer between races. He uses these differences due to the assumption that high levels of testosterone contribute to differences in prostate cancer. This claim is false.
One of my favorites is from Rushton and Templer (2012) who attempt to show that the melanocortin system modulates aggression and sexuality in humans. I wrote a response to it, and, of course, one of the main culprits is our old friend testosterone. The hypothesis put forth is, of course, another just-so story. Nevermind the fact that Rushton and Templer show no understanding of endocrinology. We have a great understanding of the melanocortin system and what it does in humans (see Cone, 2006), but, unfortunately for Rushton and Templer, none of the review discusses the fringe ideas they put forth. Rushton and Templer showed that they do not understand human physiology, much less the melanocortin system.
Lynn (2013) even claims that testosterone has an effect on human penis length between races, citing a study on… rats. RATS!! THAT is the standard of evidence that Lynn has for attempting to prove his fringe just-so stories.
These just-so stories pushed by Rushton (1997), Lynn (2006), and Hart (2007) lack independent evidence—we don’t have a time machine to verify their claims. So they’re just-so stories. I rebutted all 3 of these psycho-logists’ claims in this article on how black women do not have higher levels of T than white women. I did, indeed, used to push all types of just-so stories when I was a more hard-core “HBDer”, but I’ve since learned the errors of my ways and have stopped telling just-so stories See exhibit A, defending Kanazawa’s just-so stories.
“To be blunt, black women look more like men than women due to their higher levels of testosterone.”
I can’t believe some of the stuff that I used to write/believe… I have, of course, since seen the error of my ways (in more than one way, as can be evidenced by my view changes over the past two years).
Anyway, these types of claims are easily put to rest by reading Mazur’s (2016) analysis of testosterone and honor culture.
“There is no indication of inordinately high T among young black women with low education.”
“The pattern [high testosterone] is not seen among teenage boys or among females.”
So, quite clearly, PumpkinPerson’s just-so storytelling, as popularized by RLKH, has no backing in reality—these psycho-logists told nothing but just-so stories. “But the stories are consistent with the data!”, one may attempt to say. Well, to that, I would say the stories are selected to be consistent with the data; how parsimonious a just-so story is with any current data is irrelevant since one can spin any type of story they want to fit with any data point they have. This is put succinctly by Smith (2016) in his paper Explanations for adaptations, just-so stories, and limitations on evidence in evolutionary biology:
“An important weakness in the use of narratives for scientific purposes is that the ending is known before the narrative is constructed. … [Just-so stories] are always consistent with the observations because they are selected to be so.”
The method known as “inference to best explanation” is not a solution to these problems. … Some just-so stories should not be told.
Now, put this to the stories of RLKH, and it will become clear that all they are doing is storytelling—telling just-so stories for adults. These types of stories are inherently ad hoc and generate no testable predictions. It doesn’t matter that they “agree with the data”, since one can construct any type of narrative to agree with the data—that’s a fact.
It’s no surprise that people still, to this day, attempt to defend RLKH’s just-so storytelling—it is rooted in the Darwinian paradigm of natural selection, after all. However, appealing to an imaginary force (natural selection) which shaped traits over thousands of years is literally telling just-so stories—there is no evidence for the claim other than evidence the story purports to explain—nevermind the fact that the trait in question could have moved to fixation by other methods than “selection.” (See Samir Okasha’s (2018) book Agents and Goals in Evolution for a critique of Darwin’s view of “natural selection” with an “agent” behind it, guiding the process—Mother Nature.) Thus, RLKH et al are nothing but Darwinian just-so storytellers—and anyone who defends them as being “purveyors of truth”, people who get “shouted down” for attempting to “speak the truth” are no better than the just-so storytellers themselves.
Evolutionary Psychology (EP) is a discipline which purports to explain mental and psychological traits as adaptations—functional products of “natural selection”—which are genetically inherited/transmitted. Its main premises is that the human mind can be explained by evolution through natural selection; that the mind is “modular”—called the “massive modularity hypothesis” (see Pinker, 1997). EP purports that the mind is “a cluster of evolved information-processing mechanisms” with its main goal being “to characterize these Darwinian algorithms” (Sterelny and Griffiths, 1999: 336). The problem with EP, though, is that many of the “theories/hypotheses” are just speculation—what is termed “just-so stories” (Gould and Lewontin, 1979; Richardson, 2007; Nielsen, 2009; Fodor and Piattelli-Palmarini, 2010). In this article, I will discuss the massive modularity hypothesis, adaptationism, and the promises that EP makes as a whole.
The massive modularity hypothesis (MMH) proposes that the modules “for” mental processing evolved in response to “natural selection” (Samuels, 1998). To evolutionary psychologists, the mind is made up of different modules that were “selected for” different mental abilities. So, to evolutionary psychologists like Tooby and Cosmides, Pinker et al, much of human psychology is rooted in the Pleistocene (i.e., Tooby and Cosmides’ 5th Principle that “our modern skulls house a stone age mind“) . Evolutionary psychologists propose that the mind is made up of different, genetically influenced, modules that which were specifically selected as to help our ancestors solve domain-specific problems.
Two principle arguments exist for the MMH. Argument (1)—called the optimality argument—is:
- There are adaptive problems in every environment; different adaptive problems in different environments require different solutions, and different solutions can be implemented by functionally distinct modules.
- Adaptive problems are selective pressures; for each unique pressure faced in the original evolutionary environment (OEE), there is a unique module which was selected to solve those—and only those—specific adaptive problems.
- Selective mechanisms can produce highly specialized cognitive modules.
- Therefore, since different adaptive problems require different solutions and different solutions can be implemented by functionally distinct modules, then there must exist differing modules in the human mind which were selected for in virtue of their contribution to fitness.
Or the argument could be:
- Domain-specific processes exist
- These processes arose due to evolution
- Therefore these domain-specific processes that arose due to evolution have a genetic basis
Tooby and Cosmides claim that, distinct modules for certain adaptive problems in distinct environments are superior at solving different problems, rather than a general-purpose cognitive module. They argue that selection can produce different modules in the mind “for” different adaptive problems. Tooby and Cosmides put their argument in their own words as:
(1) As a rule, when two adaptive problems have solutions that are incompatible or simply different, a single solution will be inferior to two specialized solutions
(2) .. . domain-specific cognitive mechanisms . . . can be expected to systematically outperform (and hence preclude or replace) more general mechanisms
(3) Simply to survive and reproduce, our Pleistocene ancestors had to be good at solving an enormously broad array of adaptive problems—problems that would defeat any modern artificial intelligence system. A small sampling include foraging for food, navigating, selecting a mate, parenting, engaging in social exchange, dealing with aggressive threat, avoiding predators, avoiding pathogenic contamination, avoiding naturally occurring plant toxins, avoiding incest and so on
(4) [Therefore] The human mind can be expected to include a large number of distinct, domain-specific mechanisms (quoted from Samuels, 1998: 585-586)
Clearly, the assumption from Tooby and Cosmides is that specific modules for certain adaptive problems in the OEE are superior to general-purpose modules. Samuels (1998: 586) writes:
In the case of psychological traits, in order to use optimality considerations with any confidence one needs to know (a) what features were being optimized by the evolutionary process and (b) what range of phenotypes were available to natural selection. As a matter of fact, however, we have little knowledge about either of these matters.
The key point of the MMH is that, according to Tooby and Cosmides, we would expect that the mind consists of different modules which are “designed” to solve domain-specific problems. If we know what type of adaptive situations happened to our ancestors then we should be able to construct the evolution of a trait by knowing its current functional use and “working backwards”—what is termed “reverse engineering”—inferring “function” from “cause” (see Richardson, 2007: chapter 2); inferring effect from relevant causes (see Richardson, 2007: chapter 3) and disentangling historical ancestry from history and structure (see Richardson, 2007: chapter 4).
As for their second argument:
- It is impossible for human psychology—that contains nothing but general-purpose mechanisms—to have evolved since such a system cannot be adaptive.
- Such a system cannot possibly have solved the adaptive problems faced by our ancestors in the evolutionary past.
- Therefore, the mind cannot possibly have evolved general-purpose mechanisms and had to have evolved different mental modules in order to carry out different tasks.
They defend the argument by stating that the domain-dependence of different errors is a cause of the evolution of different modules of the mind; that information for crucial adaptive behavior cannot be learned by using only domain-specific systems; and that many adaptive problems are highly complex and unlikely to have been solved by general-purpose modules. Therefore, the mind must be modular since this can account for domain-specific problems—while, according to Tooby and Cosmides, general-purposed modules cannot. The argument, though, fails to provide us with any reason to accept the claim that the mind is made up of mostly—or is all made up of—Darwinian modules which were kept around since they were targets of selection.
Clearly, evidence for the modularity of mind is lacking—as is the evidence that reverse engineering “works” for the purpose intended.
Lloyd (1999: 224) writes that:
Given these difficulties – well-known especially since Konrad Lorenz and Nico Tinbergen’s pioneering experiments on animal behavior – it is not scientifically acceptable within evolutionary biology to conclude that, because a given pattern of responses contributes to evolutionary success, then there is some ‘organ’ (or part of the brain) producing such a pattern, that is therefore an adaptation (see Williams 1966). This is because the ‘organ’ or ‘module’ may not actually exist as a biologically real trait, and even if it does, its current function may or may not be the same as the past function(s).
Sterelny and Griffiths (1999: 342) write that “… evolutionary psychology has bought into an oversimplified view of the relationship between an evolving population and its environment, and has prematurely accepted a modular conception of the mind.”
Tooby and Cosmides (1992) coined the phrase “Standard Social Science Model” (SSSM) in order to differentiate their EP model (the “integrated causal model”; ICM) from the SSSM. According to Tooby and Cosmides (1992), the basis of the SSSM is to employ complete general-purpose cognitive modules and to deny any type of nativist modules whatsoever. Therefore, according to Tooby and Cosmides’ characterization of their so-called “opposition”, interesting differences between groups—and, of course, individuals—are due completely to cultural conditioning with absolutely no nativist elements since there are only general-purpose modules. Differences between individuals, according to the SSSM, are cultural products—differences in socialization cause individual differences.
Richardson (2007:179) writes:
Tooby and Cosmides’ portrayal [of the SSSM] is very effective. It is also a piece of sophistry, offering a false dichotomy between a manifestly untenable view and their own. The alternative is one that sees no differences between individuals and no biological contribution to individual or social development. I think no serious figure embraces that view, since, perhaps, John Watson in the early twentieth century.
Tooby and Cosmides also say that “There is no small irony in the fact that [the[ Standard Social Science MOdel’s hostility to adaptationist approaches is often justified through the accusation that adaptationist approaches purportedly attribute important differences between individuals, races and classes to genetic differences. In actuality, adaptationist approaches offer the explanation for why the psychic unity of humankind is genuine and not just an ideological fiction” (1992, 79).
Furthermore, David Buss claims that “Natural selection is the only prospect for explaining human nature” (Richardson, 2007: 182). (Whatever “human nature” is. See Nagel’s 2012 Mind and Cosmos for arguments that the mind cannot possibly have been naturally selected since evolutionary biology is a physical theory and Fodor and Pitatelli-Palmarini’s 2010 book What Darwin Got Wrong for the argument against natural selection as an explanatory mechanism in regard to trait fixation.)
Problems with the adaptationist paradigm
Adaptationism is a research programme in which, according to the Stanford Encyclopedia of Philosophy, ““adaptationists” view natural selection among individuals within a population as the only important cause of the evolution of a trait; they also typically believe that the construction of explanations based solely on natural selection to be the most fruitful way of making progress in evolutionary biology and that this endeavor addresses the most important goal of evolutionary biology, which is to understand the evolution of adaptations.”
Though numerous problems exist with this programme, not least the claim that most—or all—important phenotypic traits are the product of evolution by natural selection. In their book Sex and Death: An Introduction to Philosophy of Biology, Sterelny and Griffiths (1999: 351) write:
Adaptive explanation is an inference from the current phenotype of an organism to the problems that organism faced in its evolutionary past. Obviously, that inference will be problematic if we do not have an accurate description of the current phenotype and its adaptive significance—of the solution that evolution actually produced. The inference from current adaptive importance to adaptation is problematic enough even when the adaptive and phenotypic claims on which it is based are uncontroversial (13.1). The inference is still more problematic when the nature of the phenotype and its adaptive importance are yet to be established.
This is not the main problem with the paradigm, though. The main problem is that all of these theories/hypotheses are “just-so stories”—“… an adaptive scenario, a hypothesis about what a trait’s selective history might have been and hence what its function may be” (Sterelny and Griffiths, 1999: 61). I’d also add that just-so stories are stories that cannot be independently verified of the data that they purport to explain—that is, there is no observation that can disconfirm the adaptationist “hypothesis”, and the only data that “proves” the hypothesis is the data it purports to explain. EP hypotheses are not testable. Therefore EP hypotheses are just-so stories.
Sterelny and Griffiths (1999: 338) “… agree with the central idea of evolutionary psychology, namely, that we should look for the effects of natural selection on the psychological mechanisms that explain our behaviors, rather than on those behaviors themselves.” I disagree, since it is not possible that “psychological mechanisms” can be selected.
What is the relationship between environment and adaptation? First, we need to think of some “problems” that exist in the environment. One example is mate choice: Should one be faithful to their partner? When should one abandon their old partner? When should they help their kin find partners? When and how should one punish infidelity? This problem, pretty obviously, is evidence against the idea that adaptations are explained by the problem to which the adapted trait is the solution (see David Buller’s 2005 book Adapting Minds for strong critiques against “reverse engineering”). If—and only if—a single cognitive device exists that guides a creature’s behavior with respect to the issues of mate choice, the issue is then a single-domain, not multi-domain, problem, while there are different aspects of the same problem (see the questions above). The existence of said module explains why we think of mate choice as a single problem.
Sterelny and Griffiths (1999: 342) are hopeful in EP’s quest to discover our shared “human nature”, “But both the objective and subjective obstacles to carrying out this program remain serious.” The adaptationist programme, however, is unfalsifiable. “Particular adaptive stories can be tested, as we discuss below, but Gould and Lewontin argue that this does not test the idea of adaptationism itself. Whenever a particular adaptive story is discredited, the adaptationist makes up a new story, or just promises to look for one. The possibility that the trait is not an adaptation is never considered” (Sterelny and Griffiths, 1999: 237).
Adaptationist explanations (EP is—mostly—nothing but adaptationist explanation) are not scientific since they cannot be falsified—EP hypotheses are not falsifiable, nor do they generate testable predictions. They only explain the data it purports to explain—meaning that all EP adaptationist explanations are just-so stories. (Also see Kaplan, 2002 for arguments against the adaptationist paradigm.)
Even those who are sympathetic to the EP research programme, rightly, point out the glaring flaws in the programme. These flaws—in my opinion—cannot be overcome. EP will always be “plausible and speculatuve ” just-so stories that purport to explain the evolution of what, supposedly, are traits that were “selected for” in virtue of their contribution to fitness in the OEE. However, we do not (and cannot) know what the OEE was like—we would need a time machine. It is not possible for us to know the selective pressures that occurred on our ancestors in the OEE. We do know that increased reproductive efficiency in the current-day is not evidence that said trait was adaptive and selected in the OEE.
The mind is not modular; Tooby and Cosmides proposed a false dichotomy (their ICM vs SSSM) which is not valid (no one is a “blank slatist”, whatever that is); and the adaptationist paradigm is nothing but speculative just-so stories.
- For EP to be a valid research programme, EP hypotheses must generate testable, falsifiable predictions.
- EP cannot generate testable, falsifiable predictions (the hypotheses are inherently ad hoc).
- Therefore, EP is not a valid research programme.
There is no reason at all to accept any just-so story since these adaptive explanations cannot produce evidence that the trait was not a byproduct, due to genetic drift etc. Therefore EP is not a scientific enterprise; it only tells “plausible”, speculative stories just-so stories “… I view evolutionary psychology as more speculation than science. The conclusion I urge is, accordingly, skeptical. Speculation is just that: speculation. We should regard it as such. Evolutionary psychology as currently practiced is often speculation disguised as results. We should regard it as such” (Richardson, 2007: 25). This is the view that should be accepted in the mainstream, since there can be no evidence for the speculative stories of EP.
Evolutionary psychology (EP) purports to explain how and why humans act the way they do today. It is a framework that assumes that certain mental/psychological traits were useful in the EEA (Environment of Evolutionary Adaptedness) and thusly were selected for over time. It assumes that traits are adaptations then “works backward” by reverse engineering. Reverse engineering is the process of figuring out the design of the mechanism based on its function. (Many problems exist there which will be covered in the future; see also Evolutionary Psychology: The Burdens of Proof by Lloyd, 1999). But let’s discuss snakes and other animals that we have fears of today; is there an evolutionary basis for said behavior and can we really know if there was?
Fear of snakes and spiders
Ohman (2009: 543) writes that “Snakes … have a history measured in many millions of years of shaping mammalian and primate evolution in important respects” and that “snakes … are promising tools for probing the emotional ramifications of deep evolutionary heritages and their interaction with the current environment.” Are they promising tools, though? Were there that many snakes in our EEA that made it possible for us to ‘evolve’ these types of ‘fear modules’ (Ohman and Mineka, 2001)? No, it is impossible for our responses to snakes—along with some other animals—to be an evolved response to what occurred in our EEA because the number of venomous, dangerous snakes to humans and our ancestors was, in reality, not all that high.
Ohman and Mineka (2003: 5-6) also write that “the human dislike of snakes and the common appearances of reptiles as the embodiment of evil in myths and art might reflect an evolutionary heritage” and “fear and respect for reptiles is a likely core mammalian heritage. From this perspective, snakes and other reptiles may continue to have a special psychological significance even for humans, and considerable evidence suggests this is indeed true. Furthermore, the pattern of findings appears consistent with the evolutionary premise.”
Even the APA says that an evolutionary predisposition to fear snakes—but not spiders—exists in primates (citing research from Kawai and Koda, 2016). Conclusions such as this—and there are many others—arise from the ‘fact’ that, in our EEA, these animals were harmful to us and, over time, we evolved to fear snakes (and spiders), but there are some pretty big problems with this view.
Jankowitsch (2009) writes that “Fear of snakes and spiders, which are both considered to be common threats to survival in early human history, are not thought to be innate characteristics in human and nonhuman primates, learned.” For this to be the case, however, there would need to be many spiders and snakes in our EEA.
Philosopher of science Robert C. Richardson, in his book Evolutionary Psychology and Maladapted Psychology (Richardson, 2007) concludes that EP explanations are speculation disguised as results. He says that the stories that state that we evolved to evolved to fear snakes and spiders lack evidence. Most spiders aren’t venomous and pose no risk to humans. In the case of snakes, one quarter are poisonous to humans and we’d have to expect this ‘module’ to evolved on the basis of a minority of snakes that are poisonous to humans:
On this view, at least some human fears (but not all) are given explanations in evolutionary terms. So a fear of snakes or spiders, like our fear of strangers and heights, serves to protect us from dangers. Having observed that snakes and spiders are always scary, and not only to humans, but other primates, Steven Pinker (1997: 386) says “The common thread is obvious. These are the situations that put our evolutionary ancestors in danger. Spiders and snakes are often venomous, especially in Africa…. Fear is the emotion that motivated our ancestors to cope with the dangers they were likely to face” (cf. Nesse 1990). This is a curious view, actually. Spiders offer very little risk to humans, aside from annoyance. Most are not even venomous. There are perhaps eight species of black widow, one of the Sydney funnel web, six cases of brown recluses in North and South America, and one of the red banana spider in Latin America. These do present varying amounts of risk to humans. They are not ancestrally in Africa, our continent of origin. Given that there are over 37,000 known species of spiders, that’s a small percentage. The risk from spiders is exaggerated. The “fact” that they are “always scary” and the explanation of this fact in terms of the threat they posed to our ancestors is nonetheless one piece of lore of evolutionary psychology. Likeways, snakes have a reputation among evolutionary psychologists that is hardly deserved. In Africa, some are truly dangerous, but by no means most. About one quarter of species in Uganda pose a threat to humans, though there is geographic variability. It’s only in Australia—hardly our point of origin—that the majority of snakes are venomous. Any case for an evolved fear of snakes would need to be based on the threat from a minority. In this case too, the threat seems exaggerated. There is a good deal of mythology in the anecdotes we are offered. It is not altogether clear how the mythology gets established, but it is often repeated, with scant evidence. (pg. 28)
The important point to note here, of course, is the assumption that we have an evolved response to fear snakes (and spiders) based on a minority of actually dangerous species to humans.
The EP enterprise is built on what Gould (1978) termed “just-so stories”, borrowed from Rudyard Kipling’s (1902) book of stories called “Just So Stories” (which he told to his daughter) where he imagined ways that in which certain animals look the way they do today. These stories needed to be told “just so” or she would complain.
And the Camel said ‘Humph!’ again; but no sooner had he said it than he saw his back, that he was so proud of, puffing up and puffing up into a great big lolloping humph.
‘Do you see that?’ said the Djinn. ‘That’s your very own humph that you’ve brought upon your very own self by not working. To-day is Thursday, and you’ve done no work since Monday, when the work began. Now you are going to work.’
‘How can I,’ said the Camel, ‘with this humph on my back?’
‘That’s made a-purpose,’ said the Djinn, ‘all because you missed those three days. You will be able to work now for three days without eating, because you can live on your humph; and don’t you ever say I never did anything for you. Come out of the Desert and go to the Three, and behave. Humph yourself!’ (How the Camel got His Hump)
These stories “sound good” but is there any way to verify these nice-sounding stories? One can then make the same argument for EP hypotheses: can they be independently verified? The thing about functional verification is that we cannot possibly know the EEA of humans—or other animals—and thusly any explanation for the functionality of a certain trait are nothing but just-so stories.
Kaplan (2002: S302) argues that:
Evolutionary psychology has not yet developed the tools necessary to uncover our “shared human nature” (if such there is—see Dupre 1998) any more than physical anthropology has been able to uncover the specifics even of such clear human adaptations as our bipedalism. It is obvious that our brains were subject to selective pressures during our evolutionary history; it is not at all obvious what those pressures were.
I don’t deny that we are the products (partly, natural selection isn’t the only mode of evolution) of evolution; I do deny that these fantasy stories can tell us anything about how and why we evolved though. I don’t see how EP can develop such tools to uncover our “shared human nature”—or any other “nature” for that matter—unless time machines are developed and we can directly observe the evolution of trait X that is being discussed.
A simple argument to show that EP hypotheses are just-so stories:
P1) A just-so story is an ad-hoc hypothesis
P2) A hypothesis is ad-hoc if it’s not independently verified (verified independently of the data the hypothesis purports to explain)
P3) EP hypotheses cannot be independently verified
C) Therefore EP hypotheses are just-so stories
This simple argument shows that all EP hypotheses are just-so stories since they cannot be independently verified of the data they attempt to explain. Stories can “sound good”, they can “sound logical”, they can even be “parsimonious” and they can even be the “inference to the best explanation“, (how do you but just because these stories are “parsimonious”, “sound logical” and are the “inference to best explanation” doesn’t make the stories true. The above argument holds for one of HBD’s pet theories, too, the cold winter theory (CWT). It cannot be independently verified either, and it was formulated after national IQ differences were known; therefore CWT is a just-so story.
(I will cover this more in the future.)
Stories about snakes and spiders in our evolutionary history are likely wrong—especially if they derive from what supposedly occurred in our EEA, an environment we know almost nothing about. The fact of the matter is, regarding snakes and spiders, there is no evidence that our fear of them is an adaptive response to what occurred in our EEA. That is a just-so story. Just-so stories are ad-hoc hypotheses that cannot be independently verified, therefore EP hypotheses are just-so stories.