The Investment Model of Commitment Processes

Abstract

The investment model of commitment processes is rooted in interdependence theory and emerged from the broader scientific zeitgeist of the 1960s and 1970s that sought to understand seemingly irrational persistence in social behavior. The investment model was developed originally to move social psychology beyond focusing only on positive affect in predicting persistence in a close interpersonal relationship. As originally tested, the investment model holds that commitment to a target is influenced by three independent factors: satisfaction level, quality of alternatives, and investment size. Commitment, in turn, is posited to mediate the effects of these three bases of dependence on behavior, including persistence. Commitment is presumed to bring about persistence by influencing a host of relationship maintenance phenomena. The investment model has proven to be remarkably generalizable across a range of commitment targets, including commitment toward both interpersonal (e.g., abusive relationships, friendships) and noninterpersonal (e.g., job, sports participation, support for public policies) targets. Empirical support for the investment model is presented as well as a review of recent applications of the model and a proposed extension of it.

Introduction

The investment model (Rusbult, 1980, 1983) provides a useful framework for predicting the state of being committed to someone or something, and for understanding the underlying causes of commitment. It was developed to move beyond focusing only on positive affect in predicting persistence in an interpersonal relationship. A major premise of the investment model is that relationships persist not only because of the positive qualities that attract partners to one another (their satisfaction), but also because of the ties that bind partners to each other (their investments) and the absence of a better option beyond the relationship with the current partner (lack of alternatives); all of these factors matter in understanding commitment. Beyond explaining the antecedents of commitment, the investment model has generated a large body of research to account for what differentiates lasting relationships from those that end and on specific cognitive and behavioral [Page 219]maintenance mechanisms that are fueled by commitment. The model also has been applied to predicting commitment to all sorts of other targets, revealing its generalizability beyond close relationships.

Origins of the Investment Model

In the summer of 1976, I (CER) took a crosscountry road trip from Chapel Hill to Los Angeles. I had just completed my first year of graduate school at the University of North Carolina at Chapel Hill (UNC), and was keen to visit friends and family in LA. On the return leg of the trip my traveling companion brought up an interesting topic: “Tell me why people stick with their partners.” I spent the better part of Arizona and New Mexico describing work that seemed relevant – work regarding attitudinal similarity, physical appearance, the gain–loss phenomenon, pratfall effects, and the like. I gave a good review of the relationships literature as it existed in the mid 1970s. As we crossed the Texas border, however, my traveling companion somewhat sheepishly asked: “Okay, but can you tell me why people stick with their partners?” My companion was correct in his implied assessment of this literature. Although work regarding interpersonal attraction answers some interesting questions – for example, what makes us feel attracted to a partner, and what makes us feel satisfied with a relationship – it does not explain why people sometimes persist in relationships. The issue in this literature was positive affect, not perseverance.

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