To validate a new approach to research on the attachment behavior of children beyond toddler age, this study investigated relations between Q-sort outcomes and preschool children's affective perspective-taking; prosocial responsiveness to emotion; social competence, as rated by their teachers; and their mothers' expression and handling of emotions. Subjects were 18 children between 31 and 54 months of age and their mothers. Multiple measures were employed, including: (1) a puppet measure assessing children's affective perspective taking; (2) observation of children's prosocial reactions to emotions of peers; (3) peer sociometric ratings; (4) teacher's ratings of children's social competence on a behavior Q-sort and a problem behavior questionnaire; (5) diary records of maternal emotional displays; (6) semi-structured interviews focused on maternal emotional coping methods; and (7) mothers' trained observation of children's behavior and subsequent completion of Waters and Deane's (1985) Attachment Q-sort. Scores were correlated with 36-month criterion sorts delineating the constructs of security of attachment, dependency, and sociability. Findings reinforced the organizational view of attachment and the validity of the measurement technique, suggesting that attachment Q-sort criterion scores are related to social-emotional competence and certain aspects of maternal emotional socialization. (RH)