Social ties and social support affect mental and physical health (Thoits, 2011). This also applies in the context of work. Social support at work is related to both adverse and beneficial outcomes. Social support is consistently associated with lower levels of burnout (Day and Leiter, 2014; Lee and Ashforth, 1996) and especially when received from a supervisor, negatively associated with perceived workload (Bowling et al., 2015). In prospective studies, low social support has predicted stress-related symptoms, such as depression and anxiety, particularly among men (Nieuwenhuijsen, Bruinvels and Frings-Dresen, 2010). Lack of social support may incur billions of dollars of healthcare costs in the United States alone (Goh, Pfeffer and Zenios, 2016). Social support also fosters well-being at work. It is associated with several job attitudes, such as job satisfaction, organizational commitment, and a low level of turnover intentions (Edmondson and Boyer, 2013). Support from a supervisor appears to be especially important with regard to job attitudes (Ng and Sorensen, 2008). Social support is also consistently associated with work engagement, an active and pleasurable state of work-related well-being (Halbesleben, 2010). Thus, social support is an essential job resource, as job resources are defined as work-related characteristics facilitating goal achievement, reducing job demands and the associated strains, or stimulating growth, learning, and development (Bakker and Demerouti, 2017). However, the job demands-resources theory does not explicate the underlying mechanisms from job characteristics to outcomes (Schaufeli and Taris, 2014). One suggested explanatory mechanism for outcomes related to motivational and energetic processes of optimal functioning is satisfaction of psychological basic needs of autonomy, competence, and relatedness (Van den Broeck et al., 2008). Through their aforementioned functions (e.g. facilitating goal achievement and promoting growth), job characteristics are expected to affect the satisfaction of one or more basic needs. For example, task identity could support autonomy, whereas feedback may facilitate competence (Deci, Olafsen and Ryan, 2017). As the selfdetermination theory (SDT; Ryan and Deci, 2017) posits need satisfaction as a necessary condition for thriving, the needs are expected to act as an explanatory mechanism in the association between job resources and several outcomes. Psychological Basic Needs in the Self-Determination Theory According to the SDT, the satisfaction of the psychological basic needs of autonomy, competence, and relatedness is essential for optimal development, integrity, and wellbeing (Ryan and Deci, 2017). Each need is expected to be independently important and to have its own criteria for fulfilment. The need for autonomy is the need to experience volition, self-endorsement and ownership of actions. The need for competence is satisfied when an actor is effective in his or her interactions with the social environment, for example, expressing and expanding th...