Do Men and Women Have Different Brains?

GENDER AND OUR BRAINS
How New Neuroscience Explodes the Myths of the Male and Female Minds
By Gina Rippon

At some point or another, most books about the brain come back to the story of Phineas Gage. Gage was a railroad worker in the 19th century. In an unfortunate 1848 accident, a large steel spike was driven through his eye and out the other side of his head, taking some of his brain with him (this is the point in the story where my 8-year-old told me to please stop telling it). Amazingly, Gage survived the accident with much of his faculties intact. What did change was his personality, which, by many reports, became more aggressive and belligerent. Gage’s doctor wrote up his case, arguing that it suggested “civilized conduct” was localized in a particular part of the brain — specifically, the part he had lost.

Science was off in search of where in the brain various skills were kept, with the idea that the brain was a kind of map, with little areas for, say, walking or talking or hearing or smelling. This proceeded, albeit slowly; for a while, there wasn’t much of a way to study this other than by looking at people with traumatic brain injuries. So it’s understandable that the development of technologies to study intact brains caused a lot of excitement. Generating the most discussion in recent years has been functional magnetic resonance imaging (or fMRI), which allows researchers to measure oxygen flow to the brain and identify which parts activate in response to varying stimuli.

These technologies have not always lived up to the hype. The mechanics and statistics of processing fMRI imaging data have turned out to be far more complex than initially imagined. As a result there were many false claims made about which parts of the brain “controlled” different aspects of behavior or actions. The best, or at least funniest, example of this was a paper that showed how cutting-edge statistical analysis of fMRI made it possible to identify parts of the brain that responded differently to happy or sad faces. Sounds good, until you learn that the subject for this experiment was a dead fish.

But in spite of these failures, we’ve learned a lot. Among the more general lessons is that the brain is far more plastic — more malleable — and probably less well organized than we might imagine. Yes, there is an area of the brain that seems to process visual stimuli. But in people who cannot see, some of that area can be repurposed, for example to enhance hearing.

And this plasticity isn’t limited to major changes, either. Piano players’ brains look different from those of violin players. Researchers have shown changes in brain activity in response to a short-term intervention in which girls played Tetris regularly — their visual-spatial brain areas seemed to enlarge.

Such evidence of brain plasticity is key to Gina Rippon’s new book, “Gender and Our Brains” (which, yes, does relate the story of Phineas Gage, as well as that of the dead fish). The book is, at the core, concerned with the question of whether male and female brains are different. Rippon, a British professor of cognitive neuroimaging, reviews the history of studies of the gendered brain. The most persistent feature of these studies is the focus on size. Men have bigger brains on average, going along with their generally larger bodies, a fact that has come up again and again as an argument for male superiority, or at least structural difference. Size has fallen out of fashion, but the desire to identify gender-specific parts of the brain has not.

Rippon’s key thesis, however, is that once we recognize the existence of brain plasticity, this entire enterprise seems nonsensical. In her telling, girls and boys are treated differently from birth — even, possibly, from conception, as she relates the potential impact (far-fetched though it seems to me) of gender-reveal parties on fetal brain development. And this differential treatment will lead their brains to develop differently. If you put your boy baby in a truck onesie and your girl baby in a princess onesie, you’re already having an impact.

Given this argument, virtually any evidence we might have about differences between male and female brains is suspect. The answer may well be yes, brains appear systematically different across genders — but you’ll never know if this reflects some underlying structural difference, or whether it’s simply the result of different treatment.

This is a logical and well-taken point, but once made it is not obvious what else there is to say. The argument renders the question virtually unanswerable. In fact, the bulk of the book seems to have two aims. First, to document what evidence we do have about differences in the way male and female brains work; and, second, to discuss in detail the way boys and girls or men and women have different experiences, and how those may account for our seemingly different brains.

Perhaps befitting Rippon’s training as a neuroscientist, the evidence in her first strand is most interesting. For example, she reports on a fascinating study in which both boys and girls were shown videos of someone being injured. They were scanned in an fMRI machine while watching the videos, and brain activity in areas related to empathy was measured. The subjects were also asked how badly they felt — a direct metric of empathy. The researchers found that girls report more empathy as they age, and boys report less. But, interestingly, the brain activity shows no variation by gender at any age. It’s food for thought on how what is happening in our brain translates to what we say we feel.

One could imagine a shorter work, more focused on documenting the state-of-the-art evidence about gender differences in brain imaging. Instead the book spends most of its time in the realm of developmental psychology, or social science in general. Many of these experiments are quite interesting. My favorite involves 3-month-old infants who watched scenes in which a rabbit of one color behaved more nicely than a rabbit of another color. The babies later showed a preference for playing with the “nice” rabbit. But in this as in many other cases, it isn’t clear how the research relates to the “new neuroscience” of Rippon’s subtitle, nor does it reveal much about gender. In the nice-versus-mean rabbit experiment, gender differences were not studied at all.

Rippon is on even shakier ground in discussing, for example, differences in self-esteem between men and women, where social science convincingly demonstrates that differences exist but brain science so far has little to offer. And the segment of the book on discrimination in science was interesting from where I sit as a female academic, but didn’t seem central to Rippon’s insights or aims.

Where the book really shines — not surprisingly — is in the details about the science of the brain: what we know and what we do not. Rippon’s explanation of how we’ve studied the brain in the past, and how recent technological advances are giving us increasingly precise tools to do so, is endlessly interesting. But in the end, the discussion of how all of this relates to gender plays a bit of a second fiddle. Of course, if Rippon’s ultimate claim is simply that men’s and women’s brains are not so different after all, then perhaps that is as it should be.

Emily Oster is an economics professor at Brown University and the author of “Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, From Birth to Preschool.”

GENDER AND OUR BRAINS
How New Neuroscience Explodes the Myths of the Male and Female Minds
By Gina Rippon
424 pp. Pantheon. $30.

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