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How Male and Female Brains Differ

Researchers reveal sex differences in the brain's form and function.

WebMD Feature

Reviewed By Brunilda Nazario

Recent studies highlight a long-held suspicion about the brains of males and females. They're not the same. So how does the brain of a female look and function differently from a male's brain, and what accounts for these differences?

Disparities Start Early in Life

Scientists now know that sex hormones begin to exert their influence during development of the fetus. A recent study by Israeli researchers that examined male and female brains found distinct differences in the developing fetus at just 26 weeks of pregnancy. The disparities could be seen when using an ultrasound scanner. The corpus callosum -- the bridge of nerve tissue that connects the right and left sides of the brain -- had a thicker measurement in female fetuses than in male fetuses.

Observations of adult brains show that this area may remain stronger in females. "Females seem to have language functioning in both sides of the brain," says Martha Bridge Denckla, PhD, a research scientist at Kennedy Krieger Institute.

Consider these recent findings. Researchers, using brain imaging technology that captures blood flow to "working" parts of the brain, analyzed how men and women process language. All subjects listened to a novel. When males listened, only the left hemisphere of their brains was activated. The brains of female subjects, however, showed activity on both the left and right hemispheres.