Research over the last sixty years has largely supported the 'contact hypothesis' (Allport, 1954) and made great progress in understanding under what circumstances and by which means intergroup contact improves intergroup relations (Pettigrew & Tropp, 2006). In a nutshell, positive intergroup contact improves intergroup relations, not only when experienced directly, but also indirectly in the form of extended contact (i.e., amount of intergroup contact that someone’s ingroup friends have; Wright et al., 1997).
Despite this progress, however, the state of research leaves room for improvement with regard to two main aspects, both of which we aimed to address in our paper. First, much of the existing work on intergroup contact, relied on self-reports. Although self-reports are a valid research method with many strengths, they tend to neglect the social complexity involved in direct and extended contact. A more optimal way of measuring intergroup contact is social network analysis (SNA), which advances the traditional dyadic assessment of intergroup contact by considering more comprehensive and reciprocal information that capture direct and indirect relationships within the entire social network (see Figure below). In the first study of our paper, we empirically validated the SNA approach for studying intergroup contact by using a dataset of more than 6,000 students from Germany, the Netherlands, and Sweden. Findings demonstrated that network-based contact parameters revealed the expected associations with intergroup relations, in both the majority group and the minority group.
The second shortcoming in the field of intergroup contact regards the developmental perspective. Despite an increasing number of longitudinal studies, long-term research covering a broad developmental period across multiple waves and many years is still rare. This is surprising, because literature implies important age differences concerning the experience of intergroup contact (e.g., 'impressionable years hypothesis'; Krosnick & Alwin, 1989). In a second study of our paper, we examined the development of intergroup relations in a different dataset, including a sample of 3,815 Swedish adolescents (13 to 18 years) and young adults (19 to 26 years) who were followed in multiple waves over four years. Social network data allowed us to accurately study individuals’ direct and extended contact, as validated in Study 1. Accelerated longitudinal growth models, revealed different developmental processes. In adolescence, direct and extended contact positively changed intergroup relations, while neither direct nor extended contact predicted the development of attitudes in early adulthood. Whereas the basic longitudinal relationships between contact and later attitudes tend to reveal the expected significant associations across both age groups, contact seems to become less effective with age when estimating the long-term change due to the increasing stability of intergroup attitudes.
Our findings highlight the usefulness of SNA and underscore the importance of early intergroup contact for the development of intergroup relations. An ideal setting for contact interventions, therefore, represents the school setting, which provides a stable social network for the effective experience of early intergroup experiences.