Sex and gender are often conflated or equated in everyday conversations, and most American adults believe a person’s gender is determined by sex assigned at birth. But a new study of nearly 5,000 nine and 10-year-olds found that sex and gender map onto largely distinct parts of the brain. The research gives a first insight into how sex and gender may have “measurable and unique influences” on the brain, study authors said, just as other experiences have been shown to shape the brain.

The information you need to know, sent directly to you: Download the CTV News App “Moving forward, we really need to consider both sexes and genders separately if we better want to understand the brain,” said Dr. Elvisha Dhamala, an assistant professor of psychiatry at the Feinstein Institutes for Medical Research and the Zucker Hillside Hospital in Glen Oaks, California, and a co-author of the study, published Friday in the journal Science Advances. The researchers on the new study defined sex as what was assigned to the child at birth.

In the US, clinicians make this assignment based on genitalia. Most people are assigned either female or male, according to the research; the rest are intersex, a person whose sexual or reproductive anatomy doesn’t fit this male/female binary. The researchers defined gender as an individual’s attitude, feelings and behaviours, as well as socially constructed roles.

They noted specifically that gender is not binary, meaning not all people identify as.