James E. Birren is currently Associate Director of the Center on Aging at the University of California, Los Angeles, and serves as an adjunct professor in medicine, psychiatry, and biobehavioral sciences. He is also professor emeritus of gerontology and psychology at the University of Southern California. Dr. Birren's previous postions include service as Chief of the section on aging of the National Institute of Mental Health, founding Executive Director and Dean of the Ethel Percy Andrus Gerontology Center of USC, founding Director of the Anna and Harry Borun Center for Gerontological Research at UCLA, and President of the Gerontological Society of America, the Western Gerontological Society, and the Division on Adult Development and Aging of the American Psychological Association. Dr. Birren's many awards include the Brookdale Foundation Award for Gerontological Research, the Sandoz prize for Gerontological Research, and the award for outstanding contribution to gerontology by the Canadian Association of Gerontology. Author of over 250 scholarly publications, Dr. Birren has research interests including how speed of behavior changes with age, the causes and consequences of slowed information processing in the older nervous system, the effect of age on decision-making processes, and the role of expertise in skilled occupations. He has served as a delegate to several White House Conferences on Aging and continues to have a strong interest in developing national priorities for research and education related to issues of aging. K. Warner Schaie holds an appointment as Affiliate Professor of Psychiatry and Behavioral Sciences at the University of Washington. Hw is also the Evan Pugh Professor Emeritus of Human Development and Psychology at the Pennsylvania State University. He received his Ph.D. in clinical and developmental psychology from the University of Washington, an honorary Dr. phil. from the Friedrich-Schiller University of Jena, Germany, and an honorary Sc.D. degree from West Virginia University. He received the Kleemeier Award for Distinguished Research Contributions and the Distinguished Career Contribution to Gerontology Award from the Gerontological Society of America, the MENSA lifetime career award, and the Distinguished Scientific Contributions award from the American Psychological Association. He is a past president of the APA Division of Adult Development and Aging and currently represents that Division on the APA Council of Representatives. He is author or editor of more than 60 books including the textbook Adult Development and Aging (5th edition, with S. L. Willis) and of all previous editions of the Handbook of the Psychology of Aging (with J. E. Birren or S. L. Willis). He has directed the Seattle Longitudinal Study of cognitive aging since 1956 and is the author of more than 300 journal articles and chapters on the psychology of aging. His current research interest is in the life course of adult intelligence, its antecedents and modifiability, the impact of cognitive behavior in midlife upon the integrity of brain structures in old age, the early detection of risk for dementia, as well as methodological issues in the developmental sciences.