Genetic determinism? Not so fast.

June 26, 2009 • 7:27 am

There are several items in the news today relevant to evolutionary psychology.  First, David Brooks, in The New York Times, has an op-ed piece on the excesses of evolutionary psychology.  Apparently “inspired” by a new book by Geoffey Miller, Brooks resists evo-psycho’s exaggerated claims:

Now Miller has published another book, “Spent,” in which he takes evolutionary psychology to the mall. The basic argument is that each of us is born with our own individual level of six big traits: intelligence, openness to new things, conscientiousness, agreeableness, emotional stability and extraversion. These modules are built into humans and other animals (apparently squid can be shy).

We are all narcissists, Miller asserts. We spend much of our lives trying to broadcast our excellence in these traits in order to attract mates. Even if we’re not naturally smart or outgoing, we buy products and brands that give the impression we are.

According to Miller, driving an Acura, Infiniti, Subaru or Volkswagen is a sign of high intelligence. Driving a Cadillac, Chrysler, Ford or Hummer is a sign of low intelligence. Listening to Bjork is a sign of high intelligence, while listening to Lynyrd Skynyrd is a sign of low intelligence. Watching Quentin Tarantino movies is a sign of high openness. He theorizes that teenage girls may cut themselves as a way to demonstrate their ability to withstand infections.

Evolutionary psychology has had a good run. But now there is growing pushback. Sharon Begley has a rollicking, if slightly overdrawn, takedown in the current Newsweek. And “Spent” is a sign that the theory is being used to try to explain more than it can bear.

This critique, along with Sharon Begley’s (see below), is a welcome sign that people won’t credulously accept the excessive claims of evolutionary psychology. Miller, in particular, has made a name (and some bucks) with ludicrous and insupportable claims about the genetic basis of human nature.  Now, Brook’s own critique is not perfect. He says, for example:

The second problem is one evolutionary psychology shares with economics. It’s too individualistic: individuals are born with certain traits, which they seek to maximize in the struggle for survival.

But individuals aren’t formed before they enter society. Individuals are created by social interaction. Our identities are formed by the particular rhythms of maternal attunement, by the shared webs of ideas, symbols and actions that vibrate through us second by second. Shopping isn’t merely a way to broadcast permanent, inborn traits. For some people, it’s also an activity of trying things on in the never-ending process of creating and discovering who they are.

This really says almost nothing, and ignores the fact that humans certainly evolved in a social milieu, and that some of our evolved traits must have been adaptive only in a social milieu.  How else can you explain an inborn facility to learn language?  Brooks would have been better off making the most trenchant critique of evolutionary psychology:  the tendency for many advocates to make speculations completely unsupported by evidence.  Do young girls really cut themselves to demonstrate a resistance to infection? Why isn’t it young men who do the cutting? After all, it’s the men who compete for women, and the “handicap” view of sexual selection posits that ornaments like the peacock’s tail are there to show females that males have the genes or constitution able to deal with (or at least produce) a debilitating but attractive feature.  When it comes to speculations about human behavior, we also have to worry that they could have unintended social consequences. Promoting the notion that self-mutilation might be adaptive may, for example, have the side effect of promoting its spread.

Apropos, Sharon Begley of Newsweek has just published a long critique of evolutionary psychology, a critique that is surprising for a mainline magazine. Begley beings with a critique of Thornhill and Palmer’s “adaptive rape,” hypothesis, which I also attacked in a New Republic article.  Begley then discusses some data that refute evo-psycho’s more popular claims, noting that these refutations get far less press than the original, sensationalistic claims.

Evolutionary psychology is not going quietly. It has had the field to itself, especially in the media, for almost two decades. In large part that was because early critics, led by the late evolutionary biologist Stephen Jay Gould, attacked it with arguments that went over the heads of everyone but about 19 experts in evolutionary theory. It isn’t about to give up that hegemony. Thornhill is adamant that rape is an adaptation, despite Hill’s results from his Ache study. “If a particular trait or behavior is organized to do something,” as he believes rape is, “then it is an adaptation and so was selected for by evolution,” he told me. And in the new book Spent, evolutionary psychologist Geoffrey Miller of the University of New Mexico reasserts the party line, arguing that “males have much more to gain from many acts of intercourse with multiple partners than do females,” and there is a “universal sex difference in human mate choice criteria, with men favoring younger, fertile women, and women favoring older, higher-status, richer men.” . . .

Yet evo psych remains hugely popular in the media and on college campuses, for obvious reasons. It addresses “these very sexy topics,” says Hill. “It’s all about sex and violence,” and has what he calls “an obsession with Pleistocene just-so stories.” And few people—few scientists—know about the empirical data and theoretical arguments that undercut it. “Most scientists are too busy to read studies outside their own narrow field,” he says.

It’s about time something like this was published in a place where people can see it.   Bravo, Ms. Begley!

Speaking of research whose initial lurid claims get far more press than their later refutation, consider human “behavior genes.” Case after case in which researchers claim to have found genes for depression, novelty-seeking, alcoholism, schizophrenia, and the like have later been shown to be nonrepeatable in bigger data sets, or in data from other populations.  But the failures to replicate get far less media attention than do the original claims.  One example this week: a new “meta-analysis” study in the Journal of the American Medical Association that refutes an earlier claim that a gene involved in serotonin transport causes depression.    (See here and here for popular reports about the failure to replicate).  At least in this case, Newsweek (are they on a good science kick?) highlighted the refutation.  There are, naturally, evolutionary hypotheses about why genes for depression may be adaptive; I discuss some of these in WEIT.

All this goes to show that when it comes to assertions about the genetic/evolutionary basis of human behavior, caveat emptor.

Two good pieces on evolution in Newsweek

March 29, 2009 • 9:09 am

I’m not used to seeing good critical science reporting in popular magazines, but this week’s Newsweek is a welcome exception. It contains two pieces of note.
The first is Jeremy McCarter’s analysis of Dennis Dutton’s new evolutionary-psychology book, The Art Instinct, a book that has been getting a good deal of press in the US (not so much in the UK, where it was published; I think the US is more susceptible to the wiles of evolutionary psychology). At any rate, Dutton pushes the argument that the instinct for making art is a direct adaptation selected in our ancestors because helped them acquire mates. In other words, the sonnet is just a 14-line penis. That’s a somewhat harsh caricature, but the book is in that genre of evolutionary psychology that provides intriguing stories and speculations backed up by almost no hard evidence. When I read such things, I keep telling myself “All this is as plausible as anything else.” McCarter was a student of Stephen J. Gould, and it shows in his analysis, which is remarkably critical (and on the mark) for a science-book review:

Dutton is not the first person to extend the tools of evolutionary psychology (which is what this field of inquiry is called) to humanity’s obsession with making and enjoying art. But in “The Art Instinct,” he uses a synthesis of existing approaches to propose a new “Darwinian esthetics” —a way of thinking about culture that’s informed by natural history. As a professor of the philosophy of art (at the University of Canterbury, New Zealand) and the editor of Arts & Letters Daily, the go-to site for the world’s procrastinating intellectuals, he represents an important conduit between the frequently combative fields of science and the humanities. Quite apart from its timeliness for Darwin’s bicentennial, the book deserves a look because it’s the latest in a long, long line of attempts to bring art and science together in a way that doesn’t leave one—or both—with a black eye . . .

All in all, it’s a lovely vision. I just wish somebody could convince me that it’s true.

Because, really, who knows? In his lucid and authoritative new book, “Why Evolution Is True,” Jerry A. Coyne, a biologist from the University of Chicago, decries the “scientific parlor game” of trying to find Darwinian explanations for every form of behavior. Human life in the Pleistocene is so remote that even when researchers add the knowledge gained from observing hunter-gatherer tribes active today to the fossil record, the resulting picture of our ancestors’ ways is hopelessly blurry. “The fact is,” said Coyne when I called to talk to him about the arts, “you cannot give me a human behavior for which I can’t make up a story about why it’s adaptive.”

When the book departs from theory to consider actual art and actual human beings, the strain of yoking evolution to creativity grows even more visible. According to Dutton, moderns and postmoderns are wrong to think that people can be taught to enjoy any kind of art, no matter how ugly or obscure it might be. Our human nature ensures “not only that some things in the arts will be difficult to appreciate but that appreciation of them may be impossible.” . . .

After all, evolutionary psychology has received its sharpest criticism from no less a Darwinian than Stephen Jay Gould. Until his death in 2002, he stood as one of the great champions and evangelists of science, as well as one of the most exacting critics of its tendency to overreach. He was also my teacher. When I tried to pinpoint why Dutton’s book left me unsatisfied, his lessons kept coming to mind.

According to Gould, life’s history needs to be understood not just as the result of natural forces explicable by science, but also of contingency: strange, unplanned events that change the course of everything that follows. (If not for a freak asteroid impact 65 million years ago, Gould used to say, mammals might still be small, furry creatures scurrying around a dinosaur-centric world.) No outcome of life’s history struck him as more contingent—or, consequently, more wonderful—than the human mind, a tangle of “mental machinery jury-rigged in the immensity of evolution.” He called higher mental functions like the arts “spandrels,” an architectural term for the triangular space formed when two arches meet at right angles. Though their rich decoration can make them appear to be the point of a particular design (in the domes of some medieval churches, for instance), they’re really an inadvertent byproduct of how arches work. The arts, likewise, may be one of the many adaptively useless byproducts of a complex brain that evolved to perform other tasks.

Okay, I may not be unbiased here (and thanks, Jeremy, for the book shout-out), but I am critical of books that tell the public seductive adaptive stories about why we behave as we do, but fail to back them up with evidence. It’s misleading. Maybe I should write The Science Instinct, contending that the brainiest geeks in our savannah-dwelling ancestors were particularly attractive to females.

The second piece is by the ever-intriguing Christopher Hitchens, who writes on this week’s shenanigans by the Texas Board of Education. He argues that a version of “equal time for creationism” may apply, but not in the science class:

So by all means let’s “be honest with the kids,” as Dr. Don McLeroy, the chairman of the Texas education board, wants us to be. The problem is that he is urging that the argument be taught, not in a history or in a civics class, but in a biology class. And one of his supporters on the board, Ken Mercer, has said that evolution is disproved by the absence of any transitional forms between dogs and cats. If any state in the American union gave equal time in science class to such claims, it would certainly make itself unique in the world (perhaps no shame in that). But it would also set a precedent for the sharing of the astronomy period with the teaching of astrology, or indeed of equal time as between chemistry and alchemy. Less boring perhaps, but also much less scientific and less educational . . .

Perhaps dimly aware that they don’t want a total victory, either, McLeroy and his allies now say that they ask for evolution to be taught only with all its “strengths and weaknesses.” But in this, they are surely being somewhat disingenuous. When their faction was strong enough to demand an outright ban on the teaching of what they call “Darwinism,” they had such a ban written into law in several states. Since the defeat and discredit of that policy, they have passed through several stages of what I am going to have to call evolution. First, they tried to get “secular humanism” classified as a “religion,” so that it would meet the First Amendment’s disqualification for being taught with taxpayers’ money. (That bright idea was Pat Robertson’s.) Then they came up with the formulation of “creation science,” picking up on anomalies and gaps in evolution and on differences between scientific Darwinists like Richard Dawkins and Stephen Jay Gould. Next came the ingratiating plea for “equal time”—what could be more American than that?and now we have the rebranded new coinage of “intelligent design” and the fresh complaint that its brave advocates are, so goes the title of a recent self-pitying documentary, simply “expelled” from the discourse.

It’s not just that the overwhelming majority of scientists are now convinced that evolution is inscribed in the fossil record and in the lineaments of molecular biology. It is more that evolutionists will say in advance which evidence, if found, would refute them and force them to reconsider. (“Rabbit fossils in the pre-Cambrian layer” was, I seem to remember, the response of Prof. J.B.S. Haldane.) Try asking an “intelligent design” advocate to stipulate upfront what would constitute refutation of his world view and you will easily see the difference between the scientific method and the pseudoscientific one.

Anyway, don’t just read these quotations: read both articles in their entirety. Good job, Newsweek!