The motivation to reciprocate is analyzed within the framework of interdependence theory, with focus on the process of transformation of situations. A model of transformation is presented for the motivation to reciprocate and hypotheses regarding allocation behavior and information seeking are derived. The hypotheses are tested in two experiments implementing a game where participants allocate payoff to self and other in a sequential way, with one participant able to gather costly information regarding the other's previous behavior. Individual differences in the motivation to reciprocate are assessed with the Personal Norm of Reciprocity questionnaire. Results show that participants with high motivation to reciprocate seek information regarding other's past behavior, and react to this information as the norm of reciprocity prescribes. Participants with low motivation to reciprocate prefer information regarding the future of the interaction (Study 1), or no information (Study 2), and behave in a more selfish way. Results are discussed with respect of (1) the transformation of situation process, (2) the role of reciprocity as an interpersonal motive, and (3) the validity of the individual differences measure. Copyright # 2003 John Wiley & Sons, Ltd.In situations of interdependence of outcomes, outcomes are often only one of the many components of the situation. Real-life interactions are characterized by a variety of behavioral and interpersonal options that enrich the interpersonal processes over and above the mere allocation of resources among self and others. People often choose when to interact, with whom, and under what conditions, actively shaping the interpersonal situation and their cognitive representation of it. This variety of decisions social actors encounter has been recently taken into account in research about interdependence of outcomes, as research about social dilemmas with the option to exit or enter a relationship (Orbell & Dawes, 1993;Schuessler, 1989; Stanley, Ashlock, & Tesfation, 1994), select the partner (Yamagishi & Hayashi, 1996), or move to different relationships (Gallucci, Van Lange, & Ouwerkerk, in press) testifies. These lines of research show that individuals actively change the feature of the interdependence situation in order to achieve their interpersonal goals. Following Kelley (1997), there are two main processes whereby actors can achieve their interpersonal goals: (1) by selection of situations; (2) by transformation of situations. The first process can be referred to as locomotion (Van Lange & Visser, 1999), that is, actions taken in order to change the level of interdependence among partners. The second process has been the crucial process assumed by interdependence theory (Kelley & Thibout, 1978), whereby an actor transforms a given situation according to her or his motives, and then acts upon the subjective view the transformation process provides. Whereas much of the research aimed at expanding the interdependence framework has been devoted to the analysis of ...