7. Discussion
The current longitudinal study provided evidence for a better understanding of the mechanism through which organizational factors, such as exposure to higher workload, could lead to workplace bullying, shedding light also on conditions (i.e., organizational change) that may alter such a relationship. The relationship between workload and workplace bullying is well recognized in the literature (e.g. Baillien and De Witte, 2009; Balducci et al., 2011; Spagnoli and Balducci, 2017). However, to our knowledge, the specific mechanism through which workload affects workplace bullying has not been the object of many studies so far. High levels of workload could lead to high levels of psychological strain (e.g., see Häusser et al., 2010), which, according to different scholars, may be a critical condition for the development of bullying. Leymann (1996) first postulated that psychological strain and frustration deriving from a poor work environment increase the probability of interpersonal conflict occurrence, which may then escalate into bullying episodes. Although interpersonal conflict does not necessarily coincide with bullying, it is indeed true that bullying is an escalated form of interpersonal conflict (see Zapf and Gross, 2001). As explained in the introduction, different paths may lead particularly strained employees to become the target of bullying. For example, strained employees may withdraw and reduce their performance, which particularly in a competitive work environment may be seen as a violation of an important group norm – a well known antecedent of scapegoating and bullying (see the seminal work by Coch and French, 1948). Alternatively, strained employees may develop sinister cognitions that may lead them to become aggressive towards others and be bullied as a consequence (Neuman and Baron, 2003). The current study supported empirically the mediating role (complete mediation) of psychological strain in the relationship between workload and workplace bullying, although the specific mechanisms leading from strain to bullying were not investigated. Importantly, and in line with our third hypothesis, we found that the mediating role of psychological strain in the relationship between workload and bullying was not constant across the two groups of employees differentiated according to involvement in the organizational change process. The mediating role of psychological strain was significant only for employees who experienced organizational change between the two surveys, while it was not significant for the others, meaning that the strength of the indirect ‘effect’ depended on the experience of organizational change. Such results suggest that different work environmental factors such as high workload and the occurrence of organizational change, may interact together in creating those conditions that facilitate the development of bullying via psychological strain.
