An interesting Economist article about sex differences in a visual task calls an evolutionary explanation a “just-so story.” I don’t know if the late Stephen Jay Gould, evolutionary theorist, Harvard professor, and “one of the most influential and widely-read writers of popular science of his generation” (Wikipedia), invented this form of dismissal, but certainly he was fond of it. Here, for example:
Evolutionary biology has been severely hampered by a speculative style of argument that . . . tries to construct historical or adaptive explanations for why this bone looked like that or why this creature lived here. These speculations have been charitably called “scenarios”; they are often more contemptuously, and rightly, labeled “stories” (or “just-so stories” if they rely on the fallacious assumption that everything exists for a purpose). Scientists know that these tales are stories; unfortunately, they are presented in the professional literature where they are taken too seriously and literally.
Well, this is seriously wrong. My work contains several just-so stories — evolutionary explanations of the morning-faces effect and of the mechanism behind the Shangri-La Diet, for example. My theory of human evolution might be called a just-so saga.
These explanations made me (at least) believe more strongly in the result or theory they explained — which turned out to be a good thing. My morning-faces result was at first exceedingly implausible. The evolutionary explanation encouraged me to study it more. After repeating it hundreds of times I no longer need the evolutionary explanation to believe it but the explanation may help convince others to take it seriously. The evolutionary explanation connected with the Shangri-La Diet had the same effect. My evolutionary explanation of the effect of breakfast on sleep led me to do the experiment that discovered the morning-faces effect. My theory of human evolution led me to try new ways of teaching, with good results.
Why did Gould make this mistake? Thorstein Veblen wrote about our fondness for “invidious comparisons.” We like to say our X is better than someone else’s X. Sure, evolutionary explanations may be hard to test. That doesn’t mean they’re worthless. Like many scientists, Gould failed to grasp that something is better than nothing.
Addendum: Perhaps the Economist writer had read a recent Bad Science column that began:
I want you to know that I love evolutionary psychologists, because the ideas, like “girls prefer pink because they need to be better at hunting berries” are so much fun. Sure there are problems, like, we don’t know a lot about life in the pleistocene period through which humans evolved; their claims sound a bit like “just so” stories, relying on their own internal, circular logic; the existing evidence for genetic influence on behaviour, emotion, and cognition, is coarse; they only pick the behaviours which they think they can explain while leaving the rest; and they get themselves in massive trouble as soon as they go beyond examining broad categories of human behaviors across societies and cultures, becoming crassly ethnocentric.
“They only pick the behaviours which they think they can explain” — how dare they!
I’m not sure you are disagreeing with Gould’s actual point: just-so stories, those which assume that “everything exists for a purpose”, are taken “too seriously” in the actual literature. That doesn’t mean that they shouldn’t exist, or that evolutionary biologists should stop constructing them (especially in dinner conversations, or just with a glass of wine); it certainly doesn’t conflict with your observation that something is better than nothing. I haven’t found evolutionary biologists (my brothers and uncle) to be reluctant to come up with just-so stories; they just don’t take the stories very seriously until they turn into testable ideas. My ornithologist/environmentalist brother did, long ago, have an American Bird column on “Facts, Inferences and Shameless Speculations” ; it’s unfortunately the case that not all scientists are good at keeping track of the differences between these categories.
I’m sure your orientation really is different from Gould’s; it’s likely that you would view an explicit list of shameless speculations as having higher value than he, and I might agree–I sometimes thought he was looking for spandrel-stories where others might look for purpose-stories. Still, as the list got longer and longer, I think you would want to put down the wine-glass and start looking down that list for something testable, i.e. something definite enough so that it might be found to be wrong. I predict that you would find that some evolutionary psychology people would be with you, indeed might be ahead of you… and that others, in particular the ones Gould is fussing about, wouldn’t. (But my predictions are mostly wrong.)
Interesting blog. It’s a tricky business. “Just so” stories make good servants but bad masters. If the just so story gives us a hypothesis we can confirm or disconfirm then it can lead to breakthroughs, as in Seth’s work on weight control or faces in the morning; if the story can’t be falsified, then it’s an appeal to intuitive plausibility and may or may not be true. But sometimes all we can do is generate hypotheses and hope that future evidence will emerge and confirm or disconfirm them. And sometimes we can theorize in a way that our theories will never be confirmed. The problem is treating hypotheses as truths — or treating hypotheses about reality as accurate representations of reality without being honest about it, which is I suspect what Gould is complaining about. It is a form of intellectual corruption that’s common.
It’s often noted that Freud is full of these just so stories that can’t be confirmed; yet a charismatic therapist can foist them on patients and convince them they are true. One problem in therapy is knowing what’s a valid insight; people can have what feels like insights that aren’t, like insights that they were sexually abused as children and that explains their difficulties; or at the fringes, insights about past lives.
It’s also useful to distinguish theorizing not based on any methodically derived evidence from insight that is. Most scientific psychology tries to theorize based on scientific evidence. But in a lot of social theory and sociology, people will state that the world is like X, without showing it, and then theorize about why. I know because I’ve done it, and it passed peer reviewers in sociology easily…