Beware of Non-Supportive Leaders : Moderating Effects of Supportive Leadership on the Risks and Effects of Workplace Bullying

Sammanfattning: The aim was to investigate how supportive leadership affects workplace bullying—both in terms of risk factors that may lead to bullying but also in terms of the effects of bullying. The thesis includes three survey studies based on different Swedish cohorts and using different research design in terms of the number of data collection waves and timeframes.Based on the association between workplace bullying and poor health—and drawing on the social learning theory, the theory of social information processing, the social identity theory, and the self-categorisation theory—a circular and multilevel interaction model was created. It is presented together with six hypotheses and an open research question.The summarised and combined results can be divided into two major parts concerning (a) two studied risk factors (role ambiguity and individual poor health), and (b) the investigated moderator (supportive leadership).The results showed that role ambiguity is a long term predictor of being exposed to bullying behaviours at work, and that a hostile work climate is a mediator for that association. The results also showed that poor general health is a predictor of future bullying exposure.The results additionally showed that a supportive leadership fully moderated the effects on exposure to bullying behaviours by (a) ambiguous roles, mediated through a hostile work climate, and (b) poor general health. The result furthermore showed that a supportive leadership have an effect on the association between exposure to bullying behaviours and health. The effect was in terms of a moderated moderation also including co-worker support.Finally, the results also pointed to direct positive effects of both supportive leadership and co-worker support on individual health as well as to a direct mitigating effect of a supportive leadership on workplace bullying.Altogether, the thesis points to very important moderating effects of a supportive leadership and especially the fundamentally destructive effects in association with nonsupportive leadership.