The Emergence of Reciprocity through Contrast and Dissonance

Within groups of interacting individuals, relationships are formed in accordance to predictions of homophily. However, group composition often dictates the kind of homophily found: choice homophily or induced homophily. In differentiated groups with evolving relationships, we can easily imagine interactions occurring by choice then eventually by an apparently random process due to the increasing homogeneity of the group. In this paper, a dynamic model of group interaction is presented. By the nature of the model, virtual groups are initially differentiated and eventually reach a state of stability, sometimes complete homogeneity. Interaction is primarily constrained by two cognitive mechanisms: contrast biases and dissonance reduction, a la Heiderian balance. The presence of mutual, affective relationships defined by frequent interaction are shown to be prevalent under the contrast condition. Furthermore, our findings show that the formation of strong triads, consisting only of strong reciprocal ties, are driven by contrast while weak and transitive triads are more driven by balance. Balance, also, tends to induce higher degrees of centralization while contrast has the opposite effect.