Dear Readers: are you interested in joining the ongoing fight against Bad Science? If you are, then like me you’ll be grateful that Amanda has pointed out Scientific American’s takedown of “pop” evolutionary psychology, which is very instructive in how to take apart suspicious-smelling scientific findings.
Buller’s article is great reading, not least because he doesn’t pull punches in his logical dissection of pop-evo-psych’s logical failings. He lists four fallacies that really strike into the heart of what I’ve always found a little bit mind-boggling about this sub-field of psychology, as well as its predecessor, sociobiology. First, he points out that there are huge gaps in what we can know about the behavior of early humans — the bedrock that much of pop-evo-psych attempts to build upon, the idea that certain behaviors and predilections we observe today evolved somewhere in the divergence of humankind from the other apes.
In and of itself, this shouldn’t be a problem; a lot of scientific fields must cope with huge gaps in observable data and knowledge, and have changed radically when new discoveries are made. The real issue here is that the “pop” wing of evolutionary psychology seems to distinguish itself by filling in the gaps with “just-so stories” that explain fragments of data with modern “common sense” ideas about, for instance, what the normal roles of men and women are. Interpreting data and generating a hypothesis to fit the available evidence is part of any scientific endeavor, but I have to agree with a lot of the skepticism about this field. Some pop-evo-psych studies seem almost intentionally designed to confirm conventional beliefs about gender roles, to continue that example. This isn’t that surprising if you consider the fact that beliefs about gender are often deeply ingrained by our cultural background, and who’s doing all this interpreting and filling in the blanks? People who indeed have a cultural background, through no fault of their own. We ought to be somewhat suspicious of any bias in this direction — the direction that “confirms what we’ve always believed.”
This story from last year about how feminists killed off the neanderthals is a shining example; it even includes the pop-evo-psych obsession with Homo neanderthalensis. As is so often the case, “scientific journalism” is at fault for exaggerating and distorting a particular claim from a scientific paper — the claim that happens to be the most sensationalistic. However, you’ll have to pardon me if I’m skeptical of the idea that scientific authors are simply being taken advantage of, with no desire for media coverage of their work. Echidne delved a little deeper and found a typical explanation: a small amount of data is used to confabulate a hypothesis that just happens to provide moral support for traditional gender roles. In this case, according to the New York Times, it’s two things. First and most ridiculously, the skeletons of Neanderthal women are very robustly built, so much so that it “seems improbable” to the authors that they stayed at home to look after children — you know, because large hearty women are much more likely to want to go deer hunting. Second, there’s an absence of archaeological remains related to small-game foraging and clothing-making — the material evidence left behind by traditional female occupations in other Pleistocene Era groups that are thought to be our ancestors.
So there you have it. They’re big women and (so far) nobody has found evidence that they stayed at home to make clothes. Now the hypothesizing begins: well, the Neanderthals ate a lot of big-game meat, so the women were probably out helping with the hunt. We’ve found male Neanderthal skeletons with a lot of fractures, which were probably gotten during big-game hunting, so it was dangerous. Since it was dangerous, women probably got killed too, which is a really bad thing in a small population where you need as many women as possible to be popping out babies. Oh ho, that’s probably why they went extinct! At this point my forehead is bruised from pounding it against a desk. (There’s a more scientific takedown of this hypothesis here, pointing out that the original paper didn’t bother to try and test the idea at all.)
Buller’s first two fallacies are basically devoted to pointing out that we simply don’t and maybe can’t know enough about early human ancestors (and their cousins, like the Neanderthals) to make these kinds of hypotheses without inserting some wild leaps of faith. And by “faith” I mean “culturally ingrained beliefs about how the world works.” I find this kind of thing very disturbing in the scientific community, because it has the tendency to reify and naturalize behaviors that may have a much more transient socio-cultural nature into “facts of life” and “natural human behavior.” That’s an egregious misuse of science, even if it’s not all the scientists fault (we can blame journalists and Newt Gingrich and general misunderstanding of how science works too). It’s a political misuse of science that reinforces the status quo.
Buller’s third fallacy also plays into the picture: pop-evo-psych is obsessed with Pleistocene-era human ancestors and Neanderthals, in part because of the core assumption that this is where human beings diverged from animals. It’s not a terrible assumption to start with, but if you focus too much on it you end up ignoring two other major possibilities about the origins of human behavior:
- it may be OLDER than this divergence, in other words behavior that we share in common with chimps, gorillas, and orangutangs;
- it may be NEWER than this divergence, in other words behavior that has come about much more recently, either because of the tremendous plasticity of the human brain, related to evidence that shows that evolutionary changes could appear in human populations in as little as 500 years, or — shocker of shockers — as part of the more malleable and variable aspects of human culture, which we can see a tremendous variety in across time and geography.
The interesting thing about these alternatives is that they potentially take us towards some rather different conclusions. Buller points out that “infidelity” may not be a single evolutionary strategy that males evolved in order to maximize their breeding opportunities in a non-conscious calculus of “will I have more offspring if I stay in this stable paired relationship, or if I sow my wild oats?” Instead, it might result from a conflict of two different strategies, one from our chimpanzee heritage and one more recently developed socio-psychological tradition of pair-bonding. If you think about human behaviors in their partly-animal aspect, then of course one reaction is “well, we can overcome that animal nature and behave differently if it will result in a better, happier world for us.” We aren’t necessarily beholden to those impulses even if we know they exist, and it’s easier for us to separate them in part because they’re classified as “animal.” On the other hand, if you think about human behaviors as part of cultures that change with relative rapidity over the millennia, then of course there’s a lot of opportunity for change there as well.
Instead, the focus on Pleistocene human forebears seems aimed directly at answering the question of “why do we behave the way we do?” with origin-stories that explain why it’s natural for humans to behave in a certain way. Humans, not animals; biologically evolved, not cultural and shifting rapidly. This era of ancient prehistory is “when humans became human,” which is why so much science journalism interprets this stuff as just-so stories, the foundational myths that explain — and in explaining justify — why the world works the way it does. And you know what? I would rather not see science used this way, to create and bolster myths that prop up society. Isn’t that what we have religion for? (Ba-doom-chik!)
Buller’s last fallacy is about how pop-evo-psych correlates stories about ancient human forebears with psychological studies on modern humans. The big flaw here is that it simply isn’t clear in many situations whether a particular human behavior is a deeply rooted evolutionary adaptation that all humans share in common, or if it stems from a set of cultural beliefs, local in time and space. The study Buller focuses on has a number of alternate hypotheses that somehow don’t lead back towards “common sense” conclusions about how it’s natural and universally human for men to get mad about women’s sexual infidelities, but not the other way around.
It is unclear why Pop EP resists the idea that the sexes share the same emotional mechanism of jealousy and that attitudinal differences are a function of differences in the beliefs processed by the mechanism. According to Pop EP, many cultural differences stem from a common human nature responding to variable local conditions. Yet cultural differences are often more profound than the sex differences that Pop EP has transformed into sensational theory. If cultural variation can result from a common nature responding to dissimilar inputs, surely sex differences in attitudes and behavior can, too.
It’s really not such a stretch, and I would be surprised if many evolutionary psychologists didn’t agree. The real tension here is in how far some scientists are willing to stretch their claims in order to generate an “interesting” hypothesis, and how skeptical we really must be in looking at scientists’ cultural and political biases in how data is cobbled together and interpreted.
Of course, it wouldn’t be science if it wasn’t open to debate, falsifiability, and skepticism, so I’d be remiss if I didn’t include this link that collects various responses to Buller from the people he’s criticized and others who see him as an implacable foe to evolutionary psychology. I haven’t read Buller’s book, so I don’t know if the characterization of his work as indicting all evolutionary psychology as bunk science is accurate. That indictment certainly seems like it would be too strong, but it certainly seems to me that there’s plenty of reason to be doubtful of certain methods and biases in some scientific fields.