Why Scientists Need to Change Their Minds

When politicians do it, we call them flip-floppers. When lovers do it, we complain they have second thoughts. When teenagers do it we call it finicky. When old folks do it we call it Alzheimer.

Somehow, though we have come to believe that scientists are supposed to change their minds. Having firmly adopted their views on specific scientific questions— What killed the dinosaurs? Is the universe infinite?—which they base on a dispassionate evaluation of empirical evidence. They are expected to willingly, even eagerly, abandon their cherished beliefs when new evidence subverts them.


Many of these changes of mind are just changes of opinion or an evolution of values. A past supporter of manned spaceflight now thinks it is pointless, while another medical practitioner no longer has moral objections to cognitive enhancement through drugs. An anthropologist is now uncomfortable with cultural relativism (as in, study the Inca practice of human sacrifice non-judgmentally). Other changes of mind have to do with failed predictions, such as that computer intelligence would soon rival humans’ intelligence.

Rare, however, are changes of mind by scientists who are identified as the leader of a contentious issue. No one who rose to fame arguing that Alzheimer’s disease is caused by sticky brain plaques and who has now been convinced by evidence that the plaques are mostly innocent bystanders, not culprits has retracted original statements.

No one who once pushed hormone replacement therapy to prevent heart attacks in menopausal women who now realizes that the drugs increase the risk of heart attacks (as well as stroke and breast cancer) has retracted original statements.

No one who cast his lot with the theory that a killer asteroid sent the dinosaurs into extinction who now reads the impact-crater evidence as implicating worldwide volcanism instead has retracted original statements.

But really, we shouldn’t be surprised. Proponents of a particular viewpoint, especially if their reputation is based on the accuracy of that viewpoint, cling to it like a drowning man hanging to life preserver. Studies that undermine their position, they say, are fatally flawed.

In truth, no study is perfect, so it would be unusual to throw out an elegant, well-supported theory because one new finding casts dispersions on it. However, it is fascinating how scientists with an intellectual stake in a particular side of a debate tend to see flaws in studies that undercut their closely held views, and to interpret and even ignore “facts” to fit their views. No wonder the historian Thomas Kuhn concluded almost 50 years ago that a particular scientific paradigm topples only when the last of its powerful adherents dies.

There are some scientists who have admitted they were wrong about something central to their reputation therefore they stand out from the pack. Physicist Marcelo Gleiser of Dartmouth breaks ranks with almost every physicist since Einstein, in now doubting that the laws of nature can be unified in a single elegant formulation. Gleiser has written dozens of papers proposing routes to the unification of gravity and quantum mechanics through everything from superstrings to extra dimensions, but now concedes, “all attempts so far have failed.” Unification may be esthetically appealing, but it is not how nature as we know it, works.

The most fascinating about face has been scientists who have long pushed (politically correct) evolutionary psychology. This field holds that we all carry genes that led to reproductive success in the Stone Age, and that as a result men are genetically driven to be promiscuous and women to be coy, that men have a biological disposition to rape and to kill mates who cheat on them, and that every human behavior is “adaptive”—that is, helpful to reproduction.


But as Harvard biologist Marc Hauser now concedes, evidence is “sorely missing” that language, morals and many other human behaviors exist because they help us mate and reproduce. And Steven Pinker, one of evil-psych’s most prominent popularizers, now admits that many human genes are changing more quickly than anyone imagined. If genes that affect brain function and therefore behavior are also evolving quickly, then we do not have the Stone Age brains that evil-psych supposes, and the field “may have to reconsider the simplifying assumption that biological evolution was pretty much over” 50,000 years ago, Pinker says. How has the view that reproduction is all, and that humans are just cavemen with better haircuts, hung on so long? “Even in science,” says neuroscientist Roger Bingham of the University of California, San Diego, “a seductive story will sometimes … outpace the data.” And withstand it, too.

Like every other psychology researcher, Harvard’s Daniel Gilbert believed that people are happier when they can change their minds. But in 2002 he and a colleague discovered that people are generally happier about irrevocable decisions: once you are locked in to a decision, you tend to focus on its positive aspects and ignore the negative ones. But if you are allowed to change your mind, you ruminate on both the positive and negative aspects of the choice, which makes you less happy. Inspired by his findings, Gilbert proposed to his girlfriend. Since the “till death” vow makes marriage an (almost) irrevocable decision, the result is that “I love my wife more than I loved my girlfriend.”


Ever since Darwin’s The Descent of Man, in which he proposed the theory of sexual selection (how some are selected to pass on their traits), his followers have extended his thoughts to encompass just about all aspects of human nature. We started with social Darwinism, which fell into disfavor after World War II because its theories justified colonialism, exploitation of labor, and eugenics. These policies were developed for reasons unrelated to Darwinian theory, but the theory was easily modified to justify them.

Later, in the 1970s, sociobiology blossomed. Sociobiologists, using insect colonies as their model, explained human behavior that seemed a puzzle — such as kindness to strangers — as originating in the way that our genes get passed on because genes are shared, in large part, with relatives. Sociobiology became controversial, however, when it attracted allegations of racism[1].

But soon after, a much broader movement burst on the scene — evolutionary psychology (evo psych). Almost all human ideas can be explained, we are told, as the functional products of natural selection in our remote ancestors. We may not know why we do things, but the evolutionary psychologist does. He knows, by the methods of science, the “truth” about shopping, voting, or tipping at restaurants.

Evolutionary psychology does not, for the most part, explain puzzling human behavior. It offers Darwinian explanations for conventional behavior that are intended to supplant traditional ones. For example, why we are sexually jealous (not fear of abandonment, but “sperm competition”); why we don’t stick to our goals (evolution gave us a kludge brain). Why music exists (to allow the few to shine among the many); why art exists (to reinforce the concept of the few that are better). Why many women don’t know when they are ovulating (if they knew, they’d never have kids); why some people rape, kill, and sleep around (our Stone Age ancestors passed on these traits via their genes). Why big banks sometimes get away with fraud (most of us haven’t evolved far enough yet so as to understand what is happening).

Evo psych or (Evil psych) also accounts for anger over trivial matters (it was once key to our survival), dreams (they increase reproductive fitness), thinking about hurt feelings (our brains evolved to learn quickly from bad experiences but slowly from the good ones-why the difference they don’t say),false memories, (there might be a murderer around that darkened corner…).

They also have explanations for: menopause (men pursuing younger women), monogamy (control of females), premenstrual syndrome (breaks up infertile relationships), romantic love (not an emotion, rather a hardwired drive to reproduce), smiling (the opposite of a cringe reaction), music (to ward off danger),and wonder at the universe (explained by how early man lived).

It feels like we just emptied out Darwin’s wastebasket. Darwinian explanations of morality, self-sacrifice, politics, and religion are all available. These more consequential behaviors seem to pose a greater problem for a Darwinian worldview because the explanations offered are especially numerous and contradictory.

Meanwhile, run-of-the-mill accounts, such as those noted above, can comfortably conflict with obvious facts about human nature. Men prefer women with big breasts, we are told, because they make fertility easier to ascertain, and primeval man unconsciously sought to spread his selfish genes. Is that so? Men typically prefer more pleasure of all kinds to less — big paychecks, big cars, big steaks, and all things female ample, but not necessarily more mouths to feed, entailing more labor.

Intelligent animals prefer abundance too. Most of them are genetically distant from us. If intelligent invertebrates should pass the test, we must go back a long way for the origin of a preference for abundance, back to the Cambrian era perhaps. Evil psych explanations do not account well for explicitly human behavior (designing 107 story buildings, painting and enjoying the Mona Lisa, holding hands with your loved one walking along the river bank). But it better maps human behavior onto Darwinian thinking, and that is the goal.

Evil psych explanations can also dispense with historical fact. For example, in Delusions of Gender (2010), Cordelia Fine recounts an evil psych explanation of why little girls are dressed in pink (their brains evolved to process emotion differently). That must have been one of the few genuine instances of rapid human evolution ever recorded (instead of over millions of years), because the practice of dressing girls in pink only took root in the twentieth century[2] But no matter. Give us Darwin; we can forget history.

The accounts can even fail as parody. Neuroscientist Vilayanur Ramachandran tried parody with “Why Do Gentlemen Prefer Blondes?”, but there is no reason not to take his explanation as seriously as all the others.

Science writer Hank Campbell offers a suggestion as to why the nonsense, both high and popular, goes largely unchallenged: “Scientists are inclined to give it a break because they cleverly use the word ‘evolutionary’ in the name.” If it sounds plausible, that is evidence that it appears to be true. But if it doesn’t sound plausible, that just shows how counterintuitive real science can be.

A number of voices of reason have been heard over the years. The best-known dissent is not religious, incidentally. Common-sense philosophers David Stove and Jerry Fodor have written books, respectively Darwinian Fairytales and What Darwin Got Wrong, assailing evil psych’s simplistic, counterintuitive assertions. Social scientists such as Steven and Hilary Rose, editors of the anthology Alas, Poor Darwin, weigh in on its ad hoc assumptions about human behavior. Journalist Sharon Begley (Newsweek 2009) notes the evolutionary psychologists’ characteristic backpedalling when challenged on extreme claims, and their comfort with hypotheses that cannot be demonstrated: From its inception, evillutionary psychology has warned that behaviors that were suppossedly advantageous 100,000 years ago ( maybe a sweet tooth) might be bad for survival today (causing obesity and from there infertility due to all the diseases that would have developed from it), so there was no point in measuring whether that trait makes people more evillutionarly fit today. Even if it doesn’t, evillutionary psychologists argue, the trait might have been adaptive long ago and therefore still be our genetic legacy. An unfortunate one, perhaps, but still our legacy. Short of a time machine, this hypothesis was and still is impossible to disprove.

Medical historian Andrew Scull, reviewing a book on psychiatry’s current legitimacy crisis (2012), writes that the theories of evillutionary psychology are “unnecessary, and get in the way of an argument that depends on no more than the self-evident proposition that all of us experience fears and anxieties, which are intensified in certain social situations and by large-scale trauma, but which cannot be termed ‘mental illnesses.'”

Indeed. At the heart of evil psych is one searing contradiction: “Evolution” is supposed to be the heart and soul of its method, yet adherents believe that nothing has fundamentally changed in at least the last quarter million years. And yet that is not the sort of obvious question one is supposed to raise about their work, is it?

In which case, evil psych really says far more about the culture that created it than about the history of the human race.

[1] http://www.thecrimson.com/article/1977/2/8/sociobiology-laying-the-foundation-for-a/

[2] Cordelia Fine, Delusions of Gender: How Our Minds, Society, and Neurosexism Create Difference, (Norton, 2010), 208


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