Investment model of commitment (Rusbult)

Caryl Rusbult's validated account of what actually holds a relationship together — and why people stay. The Investment Model proposes that commitment grows from three measurable forces: satisfaction (how rewarding the relationship feels), quality of alternatives (how appealing your options outside it seem), and investment size (how much you have put in that leaving would cost — shared years, memories, mutual friends, plans). High satisfaction, poor alternatives and heavy investment together produce a strong intention to stay. The Investment Model Scale of Rusbult, Martz and Agnew (1998) measures all four facets, and the model has held up across hundreds of studies of friendships and partnerships alike. You can sit high on one force and low on another, so this maps the footing your commitment rests on rather than a single verdict.

Empirical. The Investment Model was introduced by Caryl Rusbult in 1980 and operationalised in the widely used Investment Model Scale of Rusbult, Martz and Agnew (1998), which measures four facets — satisfaction level, quality of alternatives, investment size and commitment level — with good reliability. It is one of the most validated accounts of relationship commitment in social psychology, replicated across friendships and partnerships and many cultures. The dimensions describe the footing a relationship rests on, not its worth; a higher or lower score on any one is one pattern among many. (Investment Model Scale (Rusbult, Martz & Agnew, 1998))

Dimensions

• Satisfaction (Unfulfilled – Fulfilled) — Leaning high means the relationship feels rewarding and meets your needs for closeness, support and companionship. Leaning low means it more often leaves you wanting, falling short of what you hope for.
• Quality of alternatives (Few alternatives – Many alternatives) — Leaning high means the options outside the relationship look appealing — another partner, life on your own, or leaning on friends and family. Leaning low means you see little elsewhere that would draw you away.
• Investment size (Little invested – Deeply invested) — Leaning high means a great deal is tied to the relationship that leaving would cost you — shared years, memories, mutual friends, plans and things built together. Leaning low means little would be lost if it ended.
• Commitment (Holding loosely – Here to stay) — Leaning high means you intend to stay, feel attached, and picture the relationship lasting. Leaning low means you hold it more lightly, with less sense of a shared long-term future. In the model this is what the other three forces combine to produce.

References

• Rusbult, C. E., Martz, J. M., & Agnew, C. R. (1998). The Investment Model Scale: Measuring commitment level, satisfaction level, quality of alternatives, and investment size. Personal Relationships, 5(4), 357–387
• Rusbult, C. E. (1980). Commitment and satisfaction in romantic associations: A test of the investment model. Journal of Experimental Social Psychology, 16(2), 172–186

Related topics

• Relationship status
• What matters most in a relationship
• What you're looking for
• What you bring to a relationship
• How private you keep love
• Romantic beliefs
• Communal or exchange orientation

All topics on ArtaQuest