APA Dictionary of Psychology

a longitudinal, interdisciplinary study launched in 1990 with a heterogeneous sample of West Berlin residents 70 years of age and older. A total of 516 participants completed an intensive, 14-session battery of baseline measurements and 7 in-depth follow-up exams over 2 decades. Among the aspects of aging investigated in the study were mental and physical health, social and economic status, and overall psychological functioning, as well as how these aspects changed over time. DNA retrieved from blood samples taken from participants during the baseline sessions has added a new dimension to recent analyses of the effects of aging.