The purpose of this paper is to review and synthesize the literature on adult development and to suggest how this information can be applied to the practice of adult education. The first section discusses the nature of adult development, its definition, and key concepts. Sequential patterns of change in adulthood are examined in section 2, focusing on models formulated by Jung, Buhler, Erikson, Havighurst, Levinson, Gould, Sheehy, Loevinger, Perry, Kohlberg, and Fowler. Questions about the existence and nature of sequential models and the universality and generalizability of stage theories are aired. The next section provides a sampling of other approaches to development: the issue of personality change, the themes of work and love in adulthood, and the concept of life events and transitions. The second half of the paper explores the interrelationship between adult development and adult education, suggesting that an adult's motivation and need for education are most likely propelled by life-stage concerns and tasks. The paper concludes with practical applications of adult developmental research to adult education in the areas of program development, instruction, and counseling. (SK)