Biology and Behavior

Nearly every week, scientists report identifying a new gene linked to a particular human trait. The discoveries have provided a clearer understanding of the human condition and offered a starting point for potential cures to cancer, AIDS, cystic fibrosis and a host of other afflictions. But the ability to unravel the mysteries of DNA has led some researchers to look for genetic links to commonplace behaviors, such as sexuality, violence and risk-taking. That has spawned a sometimes passionate debate over how much biology controls destiny and whether society is relying too much on science and discounting underlying social and economic conditions. Policy-makers are trying to sort out the social ramifications and establish ground rules for genetic testing and privacy.