The anterior commissure, the second main neuron bridge between the two cerebral hemispheres, is 12% larger in the female brain. (See also Corpus Callosum.) (Fisher, Helen, PhD. The First Sex. NY: Random House, 1999, pp 11-15)

The anterior commissure, the narrow strip among the nerve fibers that connect the hemispheres, is 10%-12% larger in the female brain and in the brains of homosexual males. (Blum, Deborah. Sex on the Brain. NY: Penguin Books, 1997, pp 45-47)