被信任者社会身份复杂性对其可信性的影响

被信任者社会身份是单一的还是多样的, 这种数量差异可以体现其社会身份的复杂性。本研究探讨了被信任者社会身份复杂性(单一身份、多重身份)如何影响人们对其可信性的评价。实验1考察了被信任者社会身份复杂性对其可信性的影响以及社会距离在其中的中介作用。实验2用于检验被信任者所属群体类型(内群体、外群体)是否调节他们的社会身份复杂性对其可信性的影响。研究结果表明：被信任者多重社会身份的凸显会提高人们对其可信性的评价, 社会距离在二者之间起着完全中介作用; 群体类型对社会身份复杂性的影响具有调节作用, 社会距离的中介作用在对外群体成员的可信性评价中更为明显。

The Influence of Trustees’ Social Identity Complexity on Their Trustworthiness

Trustees’ trustworthiness is a precondition of other people trusting in them, which may be influenced by trustees’ social identity complexity. Previous literature has revealed the impact of single social identity on trustworthiness; however, few studies have examined how the multiple social identities of a trustee affect his or her trustworthiness rated by others. The structure of multiple social identities can be measured in terms of social identity complexity, a concept proposed by Roccas and Brewer in 2002, which refers to the way in which individuals subjectively represent the relationships among their multiple ingroup memberships. Concretely, individuals with low social identity complexity see their ingroups as highly overlapping and convergent, whereas those with high social identity complexity see their different ingroups as distinct and cross-cutting membership groups. Roccas and their colleagues merely concerned how individuals perceive their own social identities, but neglected how they represent other people’s social identities. Moreover, social identity complexity not only reflects humans’ mental representation of their own or others social identities, but also represents one’s factual quantity of social identities. In our opinion, the quantity of social identities can be defined as an index of objective social identity complexity, which role has never been paid attention to. The present study expanded Roccas and Brewer’s ideas of social identity complexity and examined how trustees’ objective social identity complexity (single social identity vs. multiple social identities) affected people’s judgment towards trustees’ trustworthiness. In Study 1, we tested the main influence of trustees’ social identity complexity on their trustworthiness. The experiment was carried out in sleepers of a train traveling from Beijing to Yantai city. Sixty train passengers were enrolled and randomly assigned into two conditions to read a news report about a Volkswagen car (a middle-class brand) crash respectively: one group read the report depicting the driver’s single social identity (low complexity), whereas, the other group read the report depicting the driver’s multiple social identities (high complexity). After reading, they rated the driver’s trustworthiness and social distance between themselves and the driver (trustee). The results showed that trustees’ high social identity complexity effectively reduced social distance, and led participants give a higher remark on trustees’ trustworthiness. That is to say, social distance mediated the impact of trustees’ social identity complexity on their trustworthiness. In Study 2, we examined the moderating effect of trustees’ group category on the impact of social identity complexity and social distance on their trustworthiness. One hundred and twenty college students were randomly assigned into one of four conditions in a 2 (trustees’ social identity complexity: high vs. low) × 2 (trustees’ group category: ingroup vs. outgroup) full-factorial design. The experiment materials in this study were same to Study 1, except that we used two distinct car brands (ALTO vs. BMW) to manipulate trustees’ group category (ingroup vs. outgroup). More specifically, ALTO as an under-class brand, its driver would be perceived by college students as an ingroup member; whereas, BMW as a top-class brand, its driver would be an outgroup member. The results confirmed the findings of Study 1 that trustees’ social identity complexity had a positive effect on their trustworthiness and the relationship between the two variables was mediated by social distance. Moreover, the main effect of social identity complexity and the mediating effect of social distance were moderated by the group membership of trustees, and the two effects merely occurred for outgroup trustees rather than ingroup trustees. The present study provided new findings about the correlates of trustees’ trustworthiness, more importantly, which enriched the theory of social identity complexity and previous research. Besides the theoretical contributions, the present study also had great practical implications for making people’s judgment objective and promoting the positive intergroup relationships.