Sherry L. Willis is Professor of Human Development at The Pennsylvania State University. She received her Ph.D. in Educadtional Psychology from the University of Texas at Austin.  Her research interests include:  adult cognitive development with a focus on middle age, cognitive training in later adulthood, and everyday problem solving in adulthood.  She is a co-director of the Seattle Longitudinal Study with K. Warner Schaie, and has co-authored the textbook Adult Development and Aging, Fifth Edition.  She is co-editor of two other books on midlife:  Life in the Middle (with J. Reid) and The Baby Boomers (with S. Whitbourne).  She is a Fellow of the Gerontological Society of America, the American Psychological Society, and Divisions 15 and 20 of the American Psychological Association, and a past-president of APA Division 20, Adult Development and Aging (1993-1994).  In 1992, she received the Pattishall Distinguished Research Award and in 1999 the Pennsylvania State University Faculty Scholar Medal for Outstanding Achievement.

Mike Martin is Professor for Gerontopsychology and Director of the Center of Gerontology at The University of Zurich, Switzerland.  He received a Master's Degree at the University of Georgia, his Ph.D. in Developmental Psychology at The University of Mainz, Germany, and his habilitation at The German Center for Research on Ageing at The University of Heidelberg.  His research focuses on longitudinal and experimental studies of cognitive and social development across the lifespan, including studies examining predictors of development in childhood, middle adulthood, old, and extreme old age.  Recent publications include an encyclopedia of gerontology and a textbook on the psychological aspects of aging.