In all social interactions, people are interdependent – meaning each person’s actions can affect their own and other’s outcomes. Yet, people do not have objective knowledge of the type of interdependence that characterizes any specific interaction. Nonetheless, people have an ability to make inferences about the type of interdependence in a situation and The Amsterdam Cooperation Lab has recently developed a theory (i.e., Functional Interdependence Theory; FIT) and measure (Situational Interdependence Scale; SIS) about this phenomenon.

Balliet, D., Tybur, J. M., & Van Lange, P. A. M. (2017). Functional interdependence theory: An evolutionary account of social situations. Personality and Social Psychology Review, 21, 361-388.

Gerpott, F. H., Balliet, D., Columbus, S., Molho, C., & De Vries, R. E. (2018). How Do People Think About Interdependence? A Multidimensional Model of Subjective Outcome Interdependence. Journal of Personality and Social Psychology, 115, 716-742.

The Situational Interdependence Scale (SIS) measures five dimensions that characterize how people think about their interdependence with others.

Mutual Dependence: Degree of how much each person’s outcomes are determined by how each person behaves in that situation.

Power: Degree to which an individual determines their own and others’ outcomes, while others do not influence their own outcome.

Conflict: Degree to which the behavior that results in the best outcome for one individual results in the worst outcome for the other.

Future Interdependence: Degree to which own and others’ behavior in the present situation can affect own and others behavior and outcomes in future interactions.

Information Certainty: Degree to which a person knows their partner’s preferred outcomes and how each person’s actions influence each other’s outcomes.

When using the scale, the researcher or practitioner should refer the respondent to a specified situation (see instructions). Below you can download the 30-Item and 10-Item versions of the SIS in English, Dutch, German, and Chinese. If you have any questions about using the scale, contact Daniel Balliet (d.p.balliet(at)

SIS – 30 Item English Version

SIS – 10 Item English Version

SIS – 30 Item & 10-Item Dutch Version

SIS – 30 Item & 10-Item German Version

SIS – 30 Item and 10-Item Chinese Version