The paper presents findings of an empirical study of impact of psychological appraisal of a situation on frequency and motivation of observance by students of pro-social norms of behavior. The study registered relative frequency of manifestations of moral consciousness (autonomous morality, conventional morality; pre-moral and non-moral levels) in students' explanations of reasons for normative behavior in three hypothetical situations varying in three aspects: influence of observance/non-observance of the norm on the partner's well-being; outside control; possibility of sanctions when the norm is not observed. It was discovered that the most frequently manifested level of the students' motivation is that of autonomous morality; the least frequently manifested is the pre-moral level. The level of autonomous morality is usually manifested and conventional norms of behavior are observed in situations when the partner's well-being depends on observance of the norm. In situations of outside control and possibility of sanctions conventional morality is usually manifested and norms of behavior are less frequently observed.