Workplace Loneliness and Job Performance: Does Training Effectiveness and Person‐Supervisor Fit Matter?

ABSTRACT Workplace loneliness exerts well‐documented adverse effects on employee well‐being and job performance. Yet the organizational processes through which these effects unfold remain underexplored. Drawing on Social Exchange Theory, Conservation of Resources Theory, and Social Learning Theory, this study proposes and tests training effectiveness as a theoretically grounded mediating mechanism. Loneliness depletes the motivational and socio‐emotional resources that productive training engagement requires, which in turn constrains job performance. We further examine whether person‐supervisor fit moderates the negative effect of workplace loneliness on training effectiveness, arguing that a compatible supervisor functions as a proximal relational resource that can partially offset the socio‐emotional depletion associated with loneliness. Results from a time‐lagged dyadic field study drawing on data from 87 supervisors and 451 subordinates across two organizations support all four hypothesized relationships. We discuss theoretical contributions to workplace loneliness, training effectiveness, and person‐environment fit literatures and offer practical implications for organizations seeking to protect their training investments under conditions of relational scarcity at work.