There is no such thing called a “male brain” and a “female brain”, suggests new research that found no sex difference in the size of he hippocampus, a crucial part of the brain that consolidates new memories and helps connect emotions to the senses.┬áHippocampi are located on both sides of the brain, under the cerebral cortex.
The findings challenge the common claim that a disproportionately larger hippocampus explains females’ tendency toward greater emotional expressiveness, stronger interpersonal skills, and better verbal memory. “Many people believe there is such a thing as a ‘male brain’ and a ‘female brain,'” said lead researcher Lise Eliot, associate professor of neuroscience at Rosalind Franklin University of Medicine and Science in North Chicago, Illinois, US.
“But when you look beyond the popularised studies — at collections of all the data — you often find that the differences are minimal,” Eliot explained. The team examined findings from 76 published papers, involving more than 6,000 healthy individuals.
“Sex differences in the brain are irresistible to those looking to explain stereotypic differences between men and women,” Eliot said. “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,” Eliot pointed out.
Meta-analyses by other investigators have also disproved other purported sex differences in the brain, Eliot noted. Meta-analysis is a statistical technique that allows researchers to combine the findings from many independent studies into a comprehensive review.
There is no difference in the size of the corpus callosum, white matter that allows the two sides of the brain to communicate, nor do men and women differ in the way their left and right hemispheres process language, according to the researchers. The study appeared in the journal NeuroImage.