Too much of a good thing? Curvilinear effect of instrumental social support on task performance via work engagement

Based on the Threat-to-Self-Esteem (TSE) model integrated with the Conservation of Resources (COR) theory, we proposed an inverted U-shaped curvilinear relationship between receiving instrumental social support and task performance, mediated by work engagement. Further, grounded on the TSE model, we proposed the provision of instrumental social support neutralises the curvilinear association between receiving instrumental social support and work engagement. We examined these hypotheses using two samples of South Korean employees. In Study 1, we collected three-wave data (N = 302) from employees in a manufacturing company and found curvilinear associations between receiving instrumental social support and work outcomes (i.e. work engagement and task performance), supporting the Too-Much-of-a-Good-Thing (TMGT) effects. However, we did not find support for the moderating (neutralising) effects. In Study 2, we replicated the model that was supported in Study 1 (curvilinear model), using a different sample and two-wave daily diary method (N = 530, construction employees). Overall, based on the TSE model, the COR theory, and TMGT principles, in two settings and with different methods, we found support for curvilinear associations between receiving instrumental social support and work outcomes and an indirect curvilinear effect of receiving instrumental social support on task performance via work engagement.