In the twentieth century, the social and biological sciences engaged in intense debates about the importance of nature versus nurture in determining human attributes. But recent advances in molecular biology and developmental science suggest that nature and nurture act together, and heredity may be far more open to environmental change than was once thought. This raises new social and ethical questions about the implications of inequalities in the social and material circumstances of early -even prenatal- environments that may alter an individual's heredity, health and identity. For example, can a mother's or father's malnutrition or social stress alter the heredity of her or his grandchildren? If so, who bears the responsibility? Do DNA technologies that employ racial and ethnic terms instill a sense of rigid identity, just as science tells us that human attributes are more fluid than ever? How are the common perceptions of racial and ethnic groups in America changed by this understanding? This group will draw on several disciplines to explore the new science of flexible heredity in human social and political context. We will pay particular attention to ethical concerns that might inform the relationships among flexible heredity, the existence of social inequalities wrought by stigma, poverty and pollution, and their implications for reformed social policy.