In this paper I use interdependence theory as an analytic framework for depicting the logically interconnected network of expectations that determines social interaction. The framework focuses on expectations about a partner’s goals (B) relevant to particular interdependence situations (S), and suggests that expectations about these two elements define the social situation that activates a person’s own goals (A). Together, these elements determine interaction behavior (I). This SABI framework is complementary to Mischel and Shoda’s (1995) CAPS theory of personality in its logic. It depicts a person’s interpersonal dispositions as having profiles or signatures dependent on both the expected features of situations and the expected dispositions of partners. A taxonomic theory for classifying both situations and the functionally relevant goals of interaction partners is outlined. Research on attachment theory and trust is used to illustrate the model. Finally, I suggest that people’s expectations about partners’ prosocial motivations—their perceived responsiveness toward the self—play an imperial role in social cognition, and, further, that complex SABI models can be seen as detailing a set of security operations that serve as a program for social action. SABI models detail the set of mechanisms that constitute the basic survival kit of interpersonal relations.