An empirical investigation of social relations, stress and mental health at different points in the life span is proposed. Although the value of a life-span perspective is widely recognized, unifying framework is needed within which to collect the appropriate data. This study is guided by a modified version of the convoy model of social relations. The major tenet of this model is that people develop and age protected, and sometimes made vulnerable, by a relatively stable group of relationships. The study also has a cross-national, comparative dimensional. A parallel research program with the same theoretical framework, sample, goals, measures and analyses as the proposed study is to be conducted in Japan. The proposed American component will consist of a random household sample of 1500 people (from age 5) with 400 parent-child dyads. The three specific aims of the study are: (1) To explore the basic structure, Function, and Quality of Social Relations across the life-span. (2) To examine Stressful Life Events and Daily Hassles across the life- span. (3) To assess the full Convoy model of the interrelationships of Personal Characteristics, Social Relations, and Stress as Predictors of Mental Health functioning. In sum, this study will examine social relations over different ages in the life span in a high quality, community based probability sample. It is designed to permit explicit comparisons with a parallel Japanese study of the same phenomena; a shedding light on the universal and culturally specific aspects of these relationships and the affects of Personal Characteristics, Social Relations, and Stress on Mental Health at different ages in the life course.