How does motivation shape bullying defending behaviours? The interplay of mediating and moderating factors

Defending against bullying is a heterogeneous behaviour, yet little is known about how distinct motivations relate to its different forms. This study aimed to examine how autonomous, introjected, and extrinsic motivation are associated with specific forms of defending, and to explore the mediating mechanism of moral disengagement, and gender, educational stage and class moral disengagement as moderators. A total of 3,313 schoolchildren (50% girls; Mage = 13.10, SD = 1.76) took part in this study. Multilevel moderated mediation results revealed that autonomous motivation was consistently associated with prosocial forms of defending (reporting, comforting, and solution-focused, the latter only among girls), whereas introjected motivation was associated only with solution-focused defending. Extrinsic motivation predicted aggressive defending and, in specific subgroups, also prosocial defending. Moral disengagement mediated the associations between motivation and aggressive defending (autonomous motivation was indirectly associated with less aggressive defending) in classrooms with high moral disengagement, whereas extrinsic motivation was indirectly associated with more aggressive defending among boys only.