Unravelling the relationship between role overload and citizenship behaviours among Canadian employees: A test of mediating and moderating effects

Building on the conservation of resources theory and self-determination theory, the present study develops and tests a moderated mediation model of organizational citizenship behaviour, in which a) emotional exhaustion serves as a mediating mechanism linking role overload with organizational citizenship behaviour, and b) supervisor autonomy support moderates the relationship between role overload and organizational citizenship behaviour through emotional exhaustion. Results of a time-lagged study of 144 workers from various Canadian organizations provided support for the hypothesized model: supervisor autonomy support buffered a negative effect of role overload on emotional exhaustion and, indirectly, organizational citizenship behaviour. This research sheds light on the intervening variables that may explain the relationship between challenge stressors and extra-role behaviours. It also provides information on managerial practices that may protect employees’ optimal functioning against an excessive workload.