The Seattle Longitudinal Study (SLS) has been a major resource for monitoring age and cohort trends in adult cognitive development, providing normative data for assessment instruments used with older adults, exploring the causes of individual differences in aging, and assessing the effects of targeted cognitive interventions within the context of a longitudinal study. It is currently funded through 1998 to study the relation between health histories and maintenance of cognitive functioning, to provide another (1998) followup of the longitudinal panels, a 7-year follow-up of a family study, and 7- and 14-year follow-ups of the cognitive training studies. It also includes the administration of a neuropsychological battery, ApoE testing of 700 subjects over the age of 60, and recruitment of subjects for eventual autopsy. The present continuation proposal has four sub-components: (1) Completion of the 7th wave data collection. Funding is sought for the assessment of a new 7th wave of 840 subjects as well as for the analyses based on the currently funded follow-up data collection in the longitudinal study. (2) Neuro-psychological assessment obtained on older panel members over age 60 will be repeated in 3-year intervals in 2000 (N = 500) and 2003 (N = 400) to obtain measures closer to subjects' death. (3) Health histories of longitudinal panel members will be updated through 1998 to assess changes in behavior-disease relationships over time. (4). Family Studies. The second generation members will be reassessed to obtain data over a 14-year period (N = 800) and data will be collected on 600 grandchildren of the original panel member to allow studies of multi-generational family similarity in cognition. Blood samples will be obtained for ApoE genotyping and lipid profiles.