The influence of sex, age, and handedness on corpus callosum morphology: A meta-analysis

Initial observations linking variation in the human corpus callosum (CC) to handedness and sex have inspired a number of investigations of individual differences in CC size and morphology. In this quantitative review, we summarize the findings from these studies and assess the magnitude of sex, age, and handedness-related variations in the size of the CC. Meta-analysis of the 43 studies indicated that although absolute CC and splenial area are larger in men than in women, CC area adjusted for brain size was larger in women. Left-handers possess slightly larger CCs than do right-handers, and CC area decreases slightly with age. The implications of these findings for theories relating cerebral laterality to sex, age, and handedness are discussed.