Developed and tested a methodology designed to assess the effect of social consequences embedded in ongoing social interaction on the pattern of that interaction. On the basis of extended observation of the interaction of 2 mother-child dyads (34-yr-old mother and 4-yr-old female and 36-yr-old mother and 5.5-yr-old male), the procedures needed to assess the effects of naturally occurring consequences on interactional patterns are detailed. Reliable mother action/child reaction patterns were identified, and the effect of maternal consequences for those patterns on the probability of their subsequent occurrence was assessed. Results indicate that positive consequences, were associated with increases, and negative consequences with decreases, in the probability of a child reacting to the next occurrence of the maternal action when compared to the base-rate probability of that action-reaction pattern. Thus consequences affected momentary shifts around the baseline probability of interactional patterns. Positive consequences were also associated with short-term increases, and negative consequences with short-term decreases, in the base-rate probability of interactional patterns.