Workplace bullying (WB) remains a serious psychosocial risk at workplaces. However, research examining WB from the perspective of perpetrators remains limited, and interventions designed for perpetrators are non-existent. Initially, a systematic review was conducted to suggest evidence-based interventions for perpetrators (1st Study of the Doctoral Thesis). Therefore, the empirical studies that examine the antecedents, mediators, moderators and outcomes of WB perpetration from the viewpoint of perpetrators were analyzed systematically. Search in Scopus, ProQuest, Science Direct, PubMed, and Web of Science electronic databases yielded 50 empirical articles in English, published between 2003-2023, in peer-reviewed journals, corresponding to the inclusion criteria. Antecedent–perpetration relationships were primarily examined based on social and aggression theories and analyzed in the silos of work or individual factors without diverse moderators and mediators, and largely lacked causality analysis. Research on outcomes of WB perpetration was rare. Perpetration was associated with task-focused, conflict-prone, poorly organized, stressful work environments, undesirable personality characteristics, and being bullied. The suggestions to curb perpetration seemed unattainable for the same management that created the toxic environment. Based on the systematic review, and as a second step, a 3-wave longitudinal research was conducted investigating whether organizational trust and justice predicted perpetration six months later, mediated by physical and psychological health. The study was based on the Conservation of Resources Theory (COR) (2nd Study of the Doctoral Thesis, 1st Empirical Study). The sample consisted of 2447 employees, mainly from Spain and Turkey, from various industries, such as services, manufacturing, and education. The results indicated that organizational injustice predicted psychological and physical health deterioration, while unexpectedly, organizational
trust also predicted lower psychological and physical health. Health conditions did not predict perpetration after three months; organizational conditions did not predict perpetration directly or indirectly after six months. As the relationship between health status and current perpetration incidents was established, active and potential perpetrators were invited to a 24-week daily and weekly study disguised under a wellness program (3rd and final Study of the Doctoral Thesis, 2nd Empirical Study). For objective data collection, participants wore fitness bands for nine months while WB perpetration events were observed. Based on the COR Theory, sleep, physical activity (PA), and being bullied were investigated as predictors of WB perpetration at a within-person level. On a between-person level, supervisory position, psychological distress and mental illnesses were control variables. The sample contained 38 employees from Spain and Turkey, with an average age of 38.84 years (SD = 11.75) from diverse sectors, with diverse professions such as finance manager, psychologist, academic, and human resources professionals. Data collection was conducted over 24 consecutive work weeks, where only 31 participants were involved in perpetration (final observations = 720). Data were analyzed using multi-level structural equation modeling decomposed into within-and-between-person variance. The results indicated that at a within-person level, increased PA as steps taken during the work week and increased reports of being bullied predicted higher reports of perpetration the same week, while sleep quality did not. Organizations should actively inhibit WB and be mindful of employees' physical activities at work or commuting to work. Managers should also be attentive to physical fatigue that employees may feel due to their responsibilities in their private lives and allow employees to rest and recuperate to inhibit negative behaviors at work. Assessing and improving organizational trust and justice practices may help employee health improve over time. To sum up, the three innovative research studies included in the present
Ph.D. thesis broadened the WB perpetration literature by (1) presenting the first systematic review from the perspective of perpetrators and bullies; by (2) showing how physical and psychological health is related to WB perpetration incidences (with monthly, weekly and daily data); by (3) demonstrating an empirical example of resource loss spirals within COR Theory; and by (4) providing evidence for organizations and policymakers to intervene against WB with more rigorous rules.