The minimal group paradigm of social categorization provides a simple and effective tool for the intergroup relations research, which has been widely used by social psychologists. In addition to the classic task procedure, random assignment procedure, the minimal group paradigm developed the new classification operations such as imagination procedure, memorization procedure, self-involvement procedure and minimal group interaction paradigm etc. Classic task procedure, random assignment procedure, imagination procedure and memorization procedure can be used in the explicit measurement of minimal group effect. And the implicit minimal group effect, it is preferred to use the memorization procedure, while researchers should be cautious to the use of classic task procedure. Therefore, the researchers should choose the use of different minimal group paradigms according to their research purpose.
In general, the new groups generated by the minimal group paradigm mainly include two types. One is the equal groups. In the early days, most of the new different groups produced by the minimal group paradigm were equal in terms of group status and group size. The other is unequal groups. Nowadays, the intergroup relations between groups with high-low or advantage-disadvantage status are gradually becoming the focus of relevent research. Furthermore, compared to the real social categorization, the minimal group paradigm has the characteristics of randomness, complete anonymity and unrelated self-interest. And the researchers are increasingly concerned with the authenticity of the task and response of minimal group paradigm.
Initially, the dependent variable of the minimal group paradigm is the allocation behavior in the group distribution matrix. In general, the Tajfel matrix is used to assign different rewards to the participants. This classic matrix is used to measure how to select the different reward strategies for the members of ingroup and outgroup, including four strategies of Fairness (F), Maximum Difference (MD), Maximum Joint Profit (MJP) and Maximum Ingroup Profit (MIP). Recent research has shown that compared to the strategy of MIP, people tended to use the strategy of MD.
The main effect of the minimal group paradigm is the ingroup favoritism, and the researchers interpret the psychological mechanism through group-inferring-self, self-inferring-group, and integrative model of social identification. Among them, the perspective of group-inferring-self includes positive self-esteem and self-stereotyping, and the perspective of self-interring-group is mainly from the explains of self-anchoring, self-projection and I-sharing. And integrative model of social identification provides a good integration of these two perspectives, which provides a new perspective for the dynamic interaction of personal self and social self. Relative to the perspective of group-inferring-self, the researchers provide more empirical support for self-inferring-group, but as to the precise psychological mechanism of the minimal group effect still need more empirical test.
In addition to the intergroup bias research, the minimal group paradigm is widely used in social cognitive processing (such as face coding and recognition, etc.), psychological preference (such selective trust and positive traits evaluation, etc.), interaction behavior (such as effective communication, cooperation, punishment and loyalty behavior, etc.) and neurophysiological reactions (such as blood pressure, cardiovascular response and face temperature response, etc.).
It is the main direction of future research to further examine the diverse procedures of the minimal group paradigm, to improve ecological validity, to explore the potential psychological mechanisms of the effects, and to strengthen the local inspection and cross-cultural research.