New research reveals that the X chromosome may be responsible not only for determining the female gender but also for the evolution of some of the most human of human traits: language, intelligence and culture.
Hear a discussion about the latest scientific discoveries into the genetical differences of the sexes.
Ericka Check, Washington biomedical correspondent, Nature Magazine and author of the article in last week's issue of Nature headlined "The X Factor"
David Page, interim director, Whitehead Institute for Biomedical Research
Nora Newcombe, professor of psychology, Temple University.