Growing Up: An expert debate on the issue of nature versus nurture prompts an intimate look at two teenagers: one boy and one girl on different continents. Who has the advantage? Follow Dr. Helen Fisher, an anthropologist and world-renowned expert on gender differences, to Africa to determine if the development of the male and female brain could be linked to our evolutionary past. The latest research on spatial ability between the sexes is revealed, and there's an unlikely connection: testosterone levels and finger length!