In this paper we describe our newly constructed Constraining and Enabling Coding System (CECS). This scheme was constructed to identify family interactions that are conceptually relevant to adolescent ego development. First, we discuss the theoretical rationale and reliability properties of the codes. We then present results of applying the scales to observations of 61 families, consisting of 2 parents and an adolescent, drawn from matched high school and psychiatric populations. All families are upper and (predominantly) upper-middle class. Each member completed the Loevinger Sentence Completion Test and then participated in a revealed-differences task, using responses to Kohlberg Moral Dilemmas as discussion stimuli. Transcripts of these audiorecorded discussions formed the data base for the family analyses. After controlling for patient status and adolescent age, adolescent and parent ego-development scores still contributed to explained variance in family interactions. Adolescent ego development was positively associated with adolescent enabling behaviors (e.g., problem solving, empathy). In contrast, there were negative correlations between constraining behaviors (e.g., devaluing, withholding) and adolescent ego development. Parental behaviors were significantly associated with (a) parent ego development, and (b) adolescent ego development. The third dimension of our system, discourse change, also showed theoretically expected strong correlations between progressive discourse change and ego development. In our discussion we comment on the importance of now proceeding to sequence analyses in order to explore questions of directionality.