In this study 27 older adults (ages 64-80) and 23 middle-aged adults (ages 35-54) were tested for moral stage, integrative complexity of social reasoning, and perspective-taking levels twice over a 4-year period. Moral reasoning stage levels did not change over time for either age group. Older adults, but not the middle-aged, showed a significant decline over time in level of moral perspective taking. Complexity of reasoning about several interpersonal social issues declined modestly in both age groups. More social-cognitive support, a higher education level, and better self-reported health were all found to be protective factors in forestalling declines in mature adults' sociocognitive reasoning, consistent with other research on cognitive measures in later life.Do time and experience systematically alter the ways in which mature adults come to think about their social and moral lives? This question has been addressed by several means in psychological research to date. Lawrence Kohlberg's (e.g., 1976) six-stage description of moral reasoning is a prototypic example of the developmental approach to social cognition. According to this framework, individuals progress gradually from a primitive, egocentric morality to a more principled, universal view, the highest levels of which even many mature adults are believed not to achieve. The sequence of these stage progressions from childhood through middle adulthood has been documented through both cross-sectional and longitudinal investigations (e.g., Colby &Kohlberg, 1987;Walker, 1989). Research on the development of these stages of reasoning in later life is sparse and entirely cross-sectional, but it generally suggests that mature adults differ little on average from midlife to at least age 75 (e.g.