Robert R. McCrae, PhD, is Research Psychologist at the Gerontology Research Center of the National Institute on Aging. He received his doctorate in personality psychology from Boston University in 1976, and has since conducted research on personality structure, assessment, and development. His recent work has centered on cross-cultural studies of personality. He has authored or coauthored over 250 articles and chapters, and with Paul T. Costa, Jr., he is author of the Revised NEO Personality Inventory. Paul T. Costa, Jr., PhD, is Chief of the Laboratory of Personality and Cognition at the