Men and women are different, but their brains—not so much. A new study debunks yet another alleged brain difference between the sexes, and it’s a big one.
For years a belief has persisted that the hippocampus—a brain area vital to memory formation and linking emotions to the senses—is larger in the brains of women than in those of men. If true, then we'd have a neat explanation for women’s alleged ability to remember events in greater detail and with heightened awareness of emotions experienced as those memories were made.
But a new study examined the results of 76 published research papers on the topic, involving more than 6,000 people, and found no significant difference in hippocampal size between men and women. The study used meta-analysis, a statistical evaluation across several studies, to conduct a comprehensive review, and arrived at a result that deflates one of the most tenacious male versus female brain beliefs still going. To sum it up in research vernacular: “the hippocampus is not sexually dimorphic.” Translated: there's no difference worth mentioning.
Source: Wikipedia
"Sex differences in the brain are irresistible to those looking to explain stereotypic differences between men and women," said Lise Eliot, PhD, study author and associate professor of neuroscience at the Rosalind Franklin University of Medicine and Science. "They often make a big splash, in spite of being based on small samples. But as we explore multiple datasets and are able to coalesce very large samples of males and females, we find these differences often disappear or are trivial."
Considering the shelves of books and articles touting differences in male and female brains, clearly this is one of those beliefs many really want to be true. We want brain-based evidence for the belief that women are more emotionally expressive than men and remember emotional events in more detail. But while there may be other biological or psychological reasons supporting such differences (if one believes they exist), differences in brain anatomy aren't significant enough to qualify.
"Many people believe there is such a thing as a 'male brain' and a 'female brain,'" Dr. Eliot said. "But when you look beyond the popularized studies—at collections of all the data—you often find that the differences are minimal."
Other alleged differences that have turned out to be myths include that the corpus callosum--the brain area that allows the brain's hemispheres to communicate--is larger in women than in men. It's not. Nor is there strong evidence suggesting that asymmetry between men's and women's brains make the brains of women more effective language processors. For more on these and plenty more marginal to nonexistent differences, check out Eliot's book, Pink Brain, Blue Brain.
The latest study will be published in the journal Neuroimage.
You can find David DiSalvo on Twitter @neuronarrative and at his website daviddisalvo.org.
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