Researchers found that many of the connections in a typical male brain run between the front and the back of the same side of the brain, whereas in women the connections are more likely to run from side to side between the left and right hemispheres of the brain.

 

This difference in the way the nerve connections in the brain are “hardwired” occurs during adolescence when many of the secondary sexual characteristics such as facial hair in men and breasts in women develop under the influence of sex hormones, the study found.