‘The Male Brain’, or How to Write a Pop Science Book without Evidence
A few years ago I read Louann Brizendine’s book, “The Female Brain”, and marveled at her ability to take weak correlations and turn them into impressively scientific-sounding “facts.”
This really is a talent, I think, though not one that has earned her many fans in the science community. That Brizendine is a trained psychiatrist, and a member of the American Board of Psychiatry and Neurology, has not helped her credibility in science circles—in fact, many feel it only makes her more culpable, since she really ought to know better.
What I think she knows, however, is that popular science books don’t have to be evidence-based to become best sellers, and she’s no doubt correct. Her just-released book, “The Male Brain”, will demonstrate that marketplace truism once again, and once again she is raising the ire of scientists.
A few examples will better illustrate why this tension exists. Brizendine likes to say that men and women are very much alike, but different in a few crucial ways. Fair enough. How are we different?
For one, she claims the “I feel what you feel part of the brain–mirror-neuron system–is larger and more active in the female brain. So women can naturally get in sync with others’ emotions by reading facial expressions, interpreting tone of voice and other nonverbal emotional cues.”
What’s interesting is that the “mirror-neuron system” at the core of her claim may or may not be a “system” at all; in fact, whether mirror neurons even exist is still a point of neuroscientific contention. At the very least, how these neurons work is debatable and there’s anything but widespread agreement about what they do. But Brizendine makes it sound as if the matter is settled and we can confidently draw sweeping conclusions.
But take another look at her statement. Is the conclusion she’s reaching a paradigm-breaking discovery? Not at all. It’s just a regurgitation of the same stereotype we’ve heard for years, that women are more empathetic, more in sync with emotions and better communicators. Only now, according to Brizendine, we have a grandiose scientific underpinning for believing it.
Here’s another claim: “Perhaps the biggest difference between the male and female brain is that men have a sexual pursuit area that is 2.5 times larger than the one in the female brain.” This statement begs the question, where exactly is this “pursuit area”? The reader shouldn’t expect an answer—at least not one with scientific validity—because in all likelihood no such “area” exists. At minimum we should be asking how this skirt-chasing control center was identified.
This is an example of a trend that has taken over popular psychology and neuroscience publishing: using correlational fMRI data (which areas of the brain show activity under various conditions) to create the appearance of solid, rigorously researched conclusions (e.g. identification of a “pursuit area”). The problem, as recent studies have shown, is that fMRI often produces different results under the same testing conditions, and no one is exactly sure why. This fracture in the reproducibility chain doesn’t necessarily invalidate fMRI results, but it should (and generally does) stop researchers from claiming that the results are conclusive. At best, they are suggestive, at least for now. As the technology improves that may change. In addition, how to interpret fMRI results is an ongoing debate.
None of those issues are a problem for Brizendine, who, like so many popular science writers, is more than willing to stake a series of claims on shaky evidence that sounds ironclad. So we shouldn’t be surprised when she says something like this:
All that testosterone drives the “Man Trance”– that glazed-eye look a man gets when he sees breasts. As a woman who was among the ranks of the early feminists, I wish I could say that men can stop themselves from entering this trance. But the truth is, they can’t. Their visual brain circuits are always on the lookout for fertile mates. Whether or not they intend to pursue a visual enticement, they have to check out the goods. CNN, 3/24/2010
Brizendine arrives at this conclusion by way of a connect-the-dots methodology: Testosterone plus “visual brain circuits” equals “man trance.” It sounds as though she’s referencing a well-researched phenomenon, and yet I can’t find even a mention of the “man trance” anywhere in PubMed or Google Scholar. Why I can’t isn’t a mystery—she made up the term. That’s fine. An author should be allowed to coin new terms, as long as the underlying facts are solid. But here’s where we have the bigger problem—they’re not. The two studies in PubMed that address the testosterone-visual circuitry connection are about the sexual behavior of birds and goldfish.
Have we developed a sophisticated method of detecting a male bird or goldfish’s entrancement with female bird and goldfish breasts? I’m pretty sure not. This does, however, illustrate another disappointing trend in pop science publishing: extrapolating what sound like compelling conclusions from preliminary (and sometimes quirky) studies–many of which won’t ever be reproduced.
The trick here, once again, is how the “conclusion” is packaged, not how well it’s supported. Every time Brizendine goes on a talk show and discusses the “man trance,” what will stick is the clever, sound-bite ready term. Whether or not the term is evidence-based won’t matter, and usually no one will ask.
Many more examples could be addressed, but I’m sure by now the point is clear: in books like Brizendine’s, we’re not getting the results of science, we’re getting a dose of scientainment. Having it delivered to us by a well-credentialed professional makes it all the more appealing, and—in the time-honored tradition of relying on the authority of “experts”—all the more unassailable.
Unfortunately, the takeaways from these books aren’t enriching the knowledge pool. Instead, they reinforce our natural tendencies to simplify, categorize and stereotype—tendencies that for most of us aren’t in need of reinforcement.