The study has three long-term objectives. First, it will lead to more effective health care services for our nation's rapidly growing elderly population, thereby fulfilling a major policy priority for older adults, namely, preventing declines in their health and independence. Second, it will generate new information regarding how activity influences aging outcomes. Although previous research has shown that activity patterns consistently relate to important aging outcomes, little is known about how the psychological and biological changes that stem from activities combine to promote successful aging. This study will reduce this knowledge gap. Third, due to the significant ethnic diversity at the study sites, the project will produce results that generalize to minority elders. This outcome is important due to the increasing ethnic diversity of our nation's aging population.