Social psychology is the field that examines the interplay between people s motives, thoughts and actions in social settings. More specifically, social psychology at Universiteit Maastricht focuses on the immediate determinants and consequences of interaction and the role of the person in this interactive setting. At the basis of this social psychology program is the research project (Vernieuwingsimpuls) of Dr. David De Cremer, which is supported by the Netherlands Organization of Scientific Research (NWO). This project is funded by NWO for a period of 5 years and uses social psychological theories to explain the motives underlying people s pro-social actions, like cooperation, in dyads, groups and society. The main aim of this project is to provide empirical support for and theoretical elaboration of the Relational Model of Cooperation (De Cremer, 1999, 2001). Briefly put, this model argues that people have a strong need to belong to social entities like groups and organizations (Baumeister & Leary, 1995). As such, people are generally very sensitive about relational information communicating whether or not they are socially excluded or accepted by their group. Therefore, one can say that people (due to their inherent social nature) are searching for relational information that satisfies this belongingness need and which provides them a certain self and an accurate image about the world surrounding them (Sedikides & Strube, 1995; Stevens & Fiske, 1995). One way of obtaining such relational information is to assess how group members or group authorities treat others. This perspective is grounded in the procedural justice literature that shows that the use of fair procedures communicates whether or not one is respected by significant others (i.e., a reflection of one s standing within the group). The degree of respect has indeed been shown to be related to the need to belong and consequently to one s behavior within groups (De Cremer, 2001). Taken together, if people experience that they are respected and that they are not excluded from important social relationships, they will experience a positive and certain self. Thus, one s need to belong will be fulfilled. In turn, this fulfillment by relational means will influence one s perceptions of trust in others, positive affect, level of group identification and control over future interactions (particularly in the context of interdependent relationships). This emergence of positive interaction features is believed to enhance intrinsic motivation to work for the group (i.e., to reciprocate the source that fulfils the relational need to belong). Finally, due to this relational process, it is argued that a transformation of motives takes place in which personal and group goals are considered interchangeable, consequently enhancing pro-socials actions like cooperation (De Cremer & Van Vugt, 1999). As this research program combines motivational, cognitive and situational perspectives to explain pro-social behavior, the project is embedded within a social psychology group at the Department of Experimental Psychology, referred to as the Maastricht Institute of Social Psychology (MISP). The major aim of MISP is to enhance insights in social psychological phenomena, with an ultimate focus on behavior. To do this, the research group addresses several topics within the social psychology literature by making use of a wide array of experimental procedures: social dilemmas, personality (e.g., social value orientation and self-monitoring) leadership, social justice (e.g., procedural fairness), identity and self (e.g., social identities, interdependent self), information processing (e.g., how do people arrive at making fairness and attitudinal judgments), message framing and persuasion, attitudes, and counterfactual thinking. In addition to this rather fundamental research approach, the social psychology research group also extends its findings to more applied settings like organizational behavior and health practices.