Social learning theory assumes that the influence of the social environment is primary in the determination of behavior. Cognitive development theory, on the other hand, posits that individuals adapt to their environment through a cognitive process, such that individuals shape the environment to their use rather than being the products of environmental influence. These competing hypotheses were tested in a naturalistic setting with a clearly defined rule-governed environment that allowed researchers to measure attitudinal and behavioral responses to rule enforcement as well as legal-development level over time. The setting was a university residential community. The research design included a quasi-experiment: two residence halls with contrasting styles of rule enforcement and two control halls. Two populations were surveyed at the beginning of fall semester and near the end of spring semester; these were a random sample of entering freshmen across all residence halls and a representative sample of all residents in the four experimental halls. The variables measured in the survey were legal development type (types of legal reasoning), approval/disapproval of 24 rule-violating behaviors, approval/disapproval of enforcing rules against the same behaviors, and reported frequency of engaging in the behaviors. The findings support the cognitive developmental hypothesis. Legal development type was the better predictor of attitudes toward rule-violating behaviors and toward enforcement of the rules, although neither legal development type nor the social learning condition predicted the frequency of engagement in the behaviors. 8 notes and 27 references