This paper describes the self-evaluation maintenance model (SEM) which suggests that much social behavior can be understood by assuming that persons are motivated to maintain a positive self-evaluation. The two processes by which one's social circumstances may affect self-evaluation, i.e., reflection and comparison, are described. The relationship between self-evaluation and self-esteem is explored. Studies in which self-esteem was measured are reviewed, and results are discussed in terms of the SEM model. A hypothesis which explains the weak relationship between measured self-esteem and the SEM model is suggested. (JAC)