Men tend to lose brain tissue earlier in the aging process and overall they lose more of it, particularly in the frontal and temporal lobes. Women tend to lose tissue in the hippocampus and parietal areas. (Carter, Rita. Mapping the Mind. CA: University of California Press, 1998, p 71)

Study: In ages 65-95 the male brain was found to shrink faster than the female brain. This does not necessarily equate with lower intellectual functions, which may depend less on total neurons and more on density of dendritic-synaptic connections. (Carper, Jean. Your Miracle Brain. NY: HarperCollins Publishers, Inc., 2000, p 18)