Susan M. McHale, PhD, is the Director of the Social Science Research Institute and a professor of human development at Pennsylvania State University. She is interested in children's and adolescents' family relationships, roles, and everyday activities. Highlighted in her work are sibling relationship dynamics and the family experiences that foster similarities and differences in the interests, attributes, and developmental trajectories of sisters and brothers. Her earlier research on children's and adolescents' family experiences served as a basis for her current interest in the family as a context for gender socialization. Together with Dr. Nan Crouter, she co-directs the Penn State Family Relationships Project, a longitudinal study of families focused on these themes that has been funded by NICHD since 1995. In two new studies, she is studying gender dynamics in a sample of two-parent African-American families in the Philadelphia, PA region and studying similar dynamics in Mexican American families in Phoenix, AZ. These longitudinal family studies have produced a rich database of information on the experiences of mothers, fathers, and siblings and these changes over time, in families from a range of backgrounds and circumstances.