Size seems to matter—for certain kinds of intelligence —according to a new study by Sandra Witelson, professor of psychiatry and behavioral neuroscience at McMaster University in Ontario.
Witelson asked 100 terminally ill cancer patients to take a series of cognitive tests. After each person died, she and her colleagues measured the volume of the subject’s cerebral hemispheres. On average, women with larger brains had performed better on verbal tests than women with smaller brains had. There was also a less pronounced association between brain size and visual-spatial ability. The results were equivalent for right-handed and nonright-handed women.