Puberty sharpens sex-based brain-network differences

A study of 1,286 people aged 8–100 using MRI finds sex differences in brain connectivity are minimal in early life but widen at puberty and persist into adulthood, in both structural and functional networks. The timing roughly tracks sex-hormone changes and may relate to differing risks of mental-health disorders between men and women. The work is a bioRxiv preprint and relies on birth sex data; some scientists caution that differences may reflect gender roles or a mosaic of brain features rather than a binary sex, so conclusions are preliminary.