RELATIONS BETWEEN PRENATAL TESTOSTERONE AND CEREBRAL LATERALIZATION IN CHILDREN

Several theorists have proposed that the sex steroid testosterone acts on the fetal brain during a critical period of development to influen ce cerebral lateralization (N. Geschwind & A. M. Galaburda, 1987; M. H ines & C. Shipley, 1984; S. F. Witelson, 1991). In the present study, relations were examined between prenatal testosterone levels in 2nd tr imester amniotic fluid and lateralization of speech, affect, and hande dness at age 10. Girls with higher prenatal testosterone levels were m ore strongly right-handed and had stronger left-hemisphere speech repr esentation. Boys with higher prenatal testosterone levels had stronger right-hemisphere specialization for the recognition of emotion. This pattern of results is most consistent with Witelson's (1991) claim tha t prenatal testosterone leads to greater lateralization of function.