Specialists from throughout the university have developed policy recommendations on genetic testing and on the ethics and scientific validity of research into behavioral genetics. Now biologists here are hoping that the social sciences can help them separate society's beliefs about sexual identity from the interpretation of physical data. Experts in law, feminism, social history and anthropology are turning to biology to illuminate their own perspectives on sex and gender. Such cross-fertilization will help Stanford unravel natural truth from social stereotype and open up a new understanding of the human body. Biologists working to learn more about the underpinnings of sex, however, are finding just how little we really know - and that the distinctions between male and female aren't always obvious or stable.
Most people understand biological sex as dictated by a combination of sex chromosomes.
If a sperm and an egg bring together two X chromosomes, the baby is a girl. Combine an X and a Y, and it is a boy. There are, however, a small but consistent number of people who don't fit an easy chromosomal definition. People with Turner's syndrome grow up as females - even with only one X chromosome. People with Klinefelter's syndrome have two X chromosomes and one Y, yet become men.