Ruth Duskin Feldman is an award-winning writer and educator. With Diane E. Papalia and Sally Wendkos Olds, she coauthored the fourth and seventh editions of "Human Development" and the eighth edition of "A Child's World". She also is coauthor, with Dr. Papalia and Cameron J. Camp, of "Adult Development and Aging". A former teacher, she has developed educational materials for all levels from elementary school through college and has prepared ancillaries to accompany the Papalia-Olds books. She is author or coauthor of four books addressed to general readers, including "Whatever Happened to the