Interdependence theory
Interdependence theory is a social exchange theory that states that interpersonal relationships are defined through interpersonal interdependence, which is "the process by which interacting people influence one another's experiences"(Van Lange & Balliet, 2014, p. 65). The most basic principle of the theory is encapsulated in the equation I = ƒ[A, B, S], which says that all interpersonal interactions (I) are a function (ƒ) of the given situation (S), plus the actions and characteristics of the individuals (A & B) in the interaction. The theory's four basic assumptions are 1) The Principle of Structure, 2) The Principle of Transformation , 3) The Principle of Interaction, and 4) The Principle of Adaption. Authors. Interdependence theory was first introduced by Harold Kelley and John Thibaut in 1959 in their book, "The Social Psychology of Groups". This book drew inspiration from social exchange theory and game theory, and provided key definitions and concepts instrumental to the development of the interdependence framework. In their second book, "Interpersonal Relations: A Theory of Interdependence," the theory was completely formalized in 1978. Harold Kelley continued the development of Interdependence theory in 2003, with the book "An Atlas of Interpersonal Situations""." This book expanded on the previous work  by adding two additional dimensions to the dimensions of interdependence, as well as by analyzing 21 specific situation types. In addition, the work of Kelly and Thibaut built on the work of Kurt Lewin, who first defined interdependence, and stated that ""The essence of a group is not the similarity or dissimilarity of its members, but their interdependence . . . A change in the state of any subpart changes the state of any other subpart . . . Every move of one member will, relatively speaking, deeply affect the other members, and the state of the group" (pp. 84–88). Four basic assumptions of interdependence theory . 1. The principle of structure (the situation). All interactions are set within the context of their given situation (known in Interdependence theory as structure). In order to best analyze this factor, Interdependence theory presents a taxonomy of situations that includes the six dimensions listed below. A key concept with the Principle of Structure is "Affordance," or what the situation affords (makes possible) for the individuals within the interaction. 2. The principle of transformation (what people make of the situation). Transformation is a psychological process through which individuals consider possible outcomes that result from both their action and the action of  others, and weigh these outcomes against possible actions and courses of actions (Rewards and costs). 3. The principle of interaction (SABI: I = ƒ[A, B, S]). The Principle of Interaction (also referred to as the SABI model) is used to assess the variable that affect any given interaction. This model states that Interactions (I) are a function (ƒ) of the situation, Person A's (A) motives, traits, and actions, plus Person B's (B) motives, traits, and actions (I = ƒ[A, B, S]). There are several factors that individuals bring to the Interaction. They are their consideration of Outcomes, Comparison  Level, and Comparison Level for Alternatives. 4. The principle of adaptation. Adaption refers to the process by where exposure to similar situations gives rise to habitual responses which have been proven to result in (on average) positive outcomes. In addition to the type of exposure based condition just described, adaptation can result based on rules of social norms. For example, person A might enter into a situation that is similar to situations he/she has experienced before, based on these previous experiences person A's actions are guided in a way in which to receive the same positive outcomes as  the previous situations produced. Similarly, social norms guide individuals toward specific, society approved, actions. Academic and practical applications. Interdependence theory has been used by academics to "analyze group dynamics, power and dependence, social comparison, conflict and cooperation, attribution and self-presentation, trust and distrust, emotions, love and commitment, coordination and communication, risk and self-regulation, performance and motivation, social development, and neuroscientific model of social interaction" (Van Lange & Balliet, 2014, p. 67). In addition, the theory provides a practical framework for understanding the underlying psychological factors that motivate other individuals in which you interact (in both personal and professional settings ), as well as providing a framework for understanding the underlying psychological factors that motivate your own actions when interacting with others. Complementary/related theories and frameworks. Sources: