Abstract
Previous research investigating the effects of social exclusion has predominantly focused on interpersonal behavior following ostracism. Divergent findings reveal either increased aggression or increased pro-social behavior. The current research comprises seven experiments focused on intergroup (as opposed to interpersonal) forms of discrimination. The first two studies establish a link between belonging and evaluative intergroup bias discrimination. The findings show that enhanced belonging (and not personal or collective self-esteem) is an outcome of intergroup discrimination among minimal and real groups. The third study introduced the cyberball manipulation to assess the effects of inclusion/ostracism. Participants who were included showed intergroup discrimination; ostracized participants did not. The fourth study sought to examine intergroup discrimination following a more blatant form of social rejection using the false feedback paradigm. Again, the included participants discriminated, even when allocating a more noxious white noise stimulus. Rejected participants did not exhibit intergroup discrimination. Following the research demonstrating the positive-negative asymmetry effect (PNAE), the fifth study afforded category members the opportunity of exhibiting positive and negative valenced intergroup discrimination. The included participants discriminated regardless of task valence. The ostracized participants discriminated on the positive, but not negative task. The sixth study tested whether intergroup discrimination would elevate if done publicly (as opposed to private). Included participants again discriminated, regardless of whether the task was public or private. The ostracized participants however, showed discriminated only when the task was public, potentially to increase the possibility of higher group inclusion. The seventh study investigated whether random inclusion and random rejection would affect intergroup discrimination levels compared to group determined inclusion/rejection. The results found that only those who were included by group members showed significant levels of intergroup discrimination. Taken together, the findings of this thesis provide support for the idea that belongingness is linked to intergroup discrimination. Firstly, heightened belonging is an outcome of intergroup discrimination. Secondly higher belonging leads to increased intergroup discrimination. The link between belonging and intergroup discrimination appeared over a variety of social groupings (i.e., gender, national, and minimal groups), across different forms of discrimination (e.g., evaluations, white noise allocations), and the findings were also consistent across both the cyberball and false feedback paradigms. The ramifications of these findings are discussed and new ideas for future research are suggested.