UC Irvine researchers have found that men and women have very different brain designs. Women have more much white matter and men more gray matter related to intelligence. Still, there are no real differences in general intelligence between the two sexes. From the UCI press release about the study:
Gray matter represents information processing centers in the brain, and white matter represents the networking of – or connections between – these processing centers.
This, according to Rex Jung, a UNM neuropsychologist and co-author of the study, may help to explain why men tend to excel in tasks requiring more local processing (like mathematics), while women tend to excel at integrating and assimilating information from distributed gray-matter regions in the brain, such as required for language facility. These two very different neurological pathways and activity centers, however, result in equivalent overall performance on broad measures of cognitive ability, such as those found on intelligence tests.