This review assesses the adequacy of several commonly employed cognitive complexity measures on the basis of five criteria: high test-retest reliability with adults, association with chronological age across childhood and adolescence, independence from intelligence and verbal abilities, association with other indices of developed social cognition, and association with measures of developed communicative functioning. Extant research indicates that only one complexity measure—Crockett's Role Category Questionnaire—is satisfactory on all these criteria, whereas Bieri's widely used measure is deficient on most. However, research to date concerning the relationship of cognitive complexity (as assessed by Crockett's measure) to communication has failed to illuminate the specific role played by complexity as opposed to other social-cognitive factors with which it is associated.