Interdependence Theory

Interdependence Theory Definition

Interdependence theory describes the structural properties that characterize interactions and the implications of such structure for human psychology. Whereas most psychological theories focus on the individual, suggesting that people behave as they do because of their unique experiences or cognitions or personalities, interdependence theory regards the relationships between people as important as the people themselves. Thus, the theory represents a much-needed model of the nature and implications of interdependence; it is a truly social psychological theory.

Background and History of Interdependence Theory

Harold Kelley and John Thibaut developed interdependence theory over the course of 4 decades, beginning in the 1950s. Its initial formulation was contemporaneous with early social exchange and game theories, with which it shares some postulates. The theory analyzes interdependence structure, identifying crucial properties of interactions and relationships, as well as interdependence processes, explaining how structure influences motivation and behavior.

Interdependence Structure

Interdependence TheoryInterdependence theory presents a formal analysis of the abstract properties of social situations. Rather than examining concrete social elements such as “professor teaches student” or “man seduces woman,” the theory identifies abstract elements such as “dependence is mutual” or “partners’ interests conflict.” Why emphasize abstract properties? Although two situations may differ in concrete ways, they may share abstract properties that cause people to think, feel, and behave in predictable ways.

The basic unit of experience is an interaction: Each of two or more people can enact any of two or more behaviors. As a result, each person experiences good versus poor outcomes, consequences that are more versus less satisfying or pleasurable. All social situations can be described in terms of six structural dimensions. Given that most situations are defined by their properties with respect to two or more structural properties, these dimensions are the building blocks of interdependence structure.

Level of dependence describes the degree to which an individual’s outcomes are influenced by another’s actions. John is more dependent on Mary to the extent that through her actions, Mary can cause John to experience good versus poor outcomes. He is independent when her actions do not influence his well-being. Thus, John’s dependence on Mary is the converse of her power over him—when John is more dependent, Mary is more powerful.

Mutuality of dependence describes the degree to which people are equally dependent. Mutual dependence exists when Mary is as dependent on John as he is on her. Unilateral dependence involves vulnerability on the part of one person, in that the less dependent person may behave as he or she wishes without concern for the other’s well-being. Mutuality constitutes balance of power, yielding fewer opportunities for exploitation and more congenial interaction.

Basis of dependence describes whether dependence rests on partner control, where John’s outcomes are governed by Mary’s unilateral actions, versus joint control, where John’s outcomes are governed by John’s and Mary’s joint actions. Partner control is absolute and externally controlled, in that John’s outcomes are entirely governed by Mary’s behavior. Joint control is contingent, in that John’s outcomes rest on coordination with Mary (e.g., if he can predict her actions, he can modify his behavior and achieve good outcomes).

Covariation of interests describes the degree to which partners’ outcomes correspond, whether events that benefit John are similarly beneficial for Mary. Covariation ranges from correspondent situations (what is good for John is good for Mary) through mixed motive situations to situations with conflicting interests (zero sum situations; i.e., what is good for John is bad for Mary). Interaction is simple when interests correspond: John can simply pursue his interests, knowing that this will also yield good outcomes for Mary. And interaction is simple when interests conflict: One person must lose if the other is to gain, so each person simply tries to win. Mixed motive situations are more complex, in that they involve a blend of cooperative and competitive motives, combining desire to benefit the other with temptation to exploit.

Temporal structure describes the fact that interactions are dynamic and evolve over time. Interaction must be understood not only in terms of the immediate outcomes produced by partners’ choices, but also in terms of the future behaviors and outcomes that are made available (or eliminated) as a result of interaction. For example, John and Mary may make an extended series of investments to develop a committed relationship. Or by behaving in a particular manner today, they may create desirable future opportunities for themselves or proceed down a path where only poor outcomes are available.

Availability of information is the sixth structural dimension. John and Mary may possess adequate versus inadequate information about their own or the other’s outcomes for various combinations of behavior (“How does Mary feel about marriage?”); a partner’s motives (“Will Mary use her power benevolently?”); or future interaction possibilities (“If we do this today, where will it take us?”). Inadequate information gives rise to ambiguity and misunderstanding, challenging the flow of interaction.

Interdependence Processes

Affordance describes what a situation makes possible or may activate in interaction partners. Specific situations present people with specific problems and opportunities and therefore logically imply the relevance of specific motives and permit the expression of those motives. For example, situations with conflicting interests afford the expression of self-centeredness versus concern with another’s well-being: John can behave in such a manner as to yield good outcomes for him or for Mary, but not for both. Therefore, conflicting interests inspire predictable sorts of cognition (greed, fear) and invite predictable forms of attribution and self-presentation (“Does Mary care about me?” “Trust me!”).

People do not always react to situations in ways that maximize their immediate outcomes. Transformation is the psychological process whereby people set aside their immediate, gut-level desires and instead react to a situation on the basis of broader considerations, including the well-being of others, long-term goals, or stable personal values. The transformation process may rest on systematic thought or automatic habits. It is through the transformation process that people reveal their social selves—motives deriving from the fact that people sometimes have a past and a future with interaction partners.

Through attribution processes, people attempt to uncover the implications of another’s actions; for example, Mary may try to discern whether John’s behavior is attributable to the situation (desire for good immediate outcomes) or to John’s transformation of the situation (intent to sacrifice his interests so as to give her good outcomes). In like manner, through self-presentation, people attempt to communicate the implications of their own actions; for example, John may try to communicate that in a given situation it is in his interest to behave selfishly, yet he has sacrificed so as to benefit Mary. People cannot communicate or discern all motives in all situations, in that specific motives are relevant to specific types of situations. For example, in situations with perfectly corresponding interests, John cannot display trustworthiness; if he behaves in ways that benefit Mary, he is likewise benefited, such that it is impossible to determine whether he is driven by self-interest or prosocial motives.

Where do the motives that guide the transformation process come from? People initially react to situations as unique problems. In a novel situation, John may carefully analyze circumstances or react impulsively. Either way, he acquires experience: If his reaction yields poor outcomes, he will behave differently in future situations with parallel structure; if his reaction yields good outcomes, he will react similarly in future, parallel situations. Repeated experience in situations with similar structure gives rise to stable transformation tendencies that on average yield good outcomes. Stable adaptations may reside within persons, relationships, or groups.

Interpersonal dispositions are actor-specific inclinations to respond to specific situations in a specific manner across numerous partners. Over the course of development, different people undergo different experiences with family members and confront different opportunities with peers. As a result, people acquire dispositions to perceive situations in specific ways, to anticipate specific motives from others, and to transform situations in predictable ways. For example, a child who encounters unresponsive caregiving may develop fearful expectations about dependence and therefore avoid situations in which she must rely on others. Thus, the interpersonal self is the sum of one’s adaptations to previous interdependence problems.

Relationship-specific motives are inclinations to respond to specific situations in a specific manner with a specific partner. For example, trust reflects an individual’s confidence in a partner’s benevolence. Mary develops trust when John behaves prosocially by departing from his immediate interests to enhance her outcomes. His actions communicate responsiveness to her needs, thereby promoting Mary’s trust in his motives, increasing her comfort with dependence, strengthening her commitment, and enhancing the odds of reciprocal benevolence.

Social norms are rule-based, socially transmitted inclinations to respond to particular situations in a specific manner. For example, societies develop rules regarding the expression of anger; such rules help groups avoid the chaos that would ensue if people were to freely express hostility. Likewise, rules of etiquette represent efficient solutions to interdependence dilemmas, regulating behavior in such a manner as to yield harmonious interaction. Sometimes behavior is influenced by societal-level norms; dyads may also develop relationship-specific norms.


  1. Kelley, H. H., Holmes, J. G., Kerr, N. L., Reis, H. T., Rusbult, C. E., & Van Lange, P. A. M. (2003). An atlas of interpersonal situations. New York: Cambridge University Press.
  2. Kelley, H. H., & Thibaut, J. W. (1978). Interpersonal relations: A theory of interdependence. New York: Wiley.
  3. Thibaut, J. W., & Kelley, H. H. (1959). The social psychology of groups. New York: Wiley.