CAMBRIDGE, England — The age-old debate about differences between male and female brains has taken a dramatic turn with new evidence suggesting these variations begin before a baby’s first cry.

not even a water pistol,” a young mother told me emphatically from the microphone in the lecture hall where I’d just given a talk on the differences between male and female brains. “But the other day ...

Structural differences between male and female brains are apparent from the very earliest days of life, according to a new study. The researchers found that even in young babies, female brains ...