On the basis of the positions of behaviors relative to one another in the interpersonal circle, the principles of complementarity and anticomplementarity specify how people's behaviors influence one another in interpersonal interactions. Pairs of undergraduate women (1 subject, N = 80, and 1 confederate) collaborated for 16 min to create and agree on stories for two pictures. Confederates performed scripted roles that emphasized one of eight interpersonal behaviors. Behaviors were coded into eight categories, and the relative effect of each confederate behavior on each subject behavior was determined. Using the geometric properties of the interpersonal circle, vectors were calculated that identified the relative impact of each confederate stimulus behavior on the overall pattern of subject responses. Results were consistent with the dynamic relations among interpersonal behaviors that complementarity and anticomplementarity propose and demonstrated that how a person behaves toward another systematically and profoundly affects how the other behaves toward the person.