Toxic traits at work: how perceived coworker dark triad behaviours deplete resources and fuel burnout

Purpose This study aims to investigate how perceived coworker dark triad (DT) traits − narcissism, Machiavellianism and psychopathy − contribute to employee burnout through the mediating role of job stress. Drawing on conservation of resources (COR) theory, the study conceptualises toxic peer behaviour as a chronic interpersonal stressor that depletes emotional and psychological resources, undermining employee well-being. Design/methodology/approach Survey data were collected from 540 professionals employed in US professional service firms. Confirmatory factor analysis was used to establish construct validity, and structural equation modelling was used to test the hypothesised relationships. Indirect effects were assessed using bootstrapping with 5,000 resamples. Findings Perceived coworker Machiavellianism and psychopathy were positively associated with job stress, which in turn predicted burnout. Direct relationships between these traits and burnout were nonsignificant, indicating full mediation through stress. These findings show that peer-driven toxicity contributes to burnout indirectly by sustaining resource depletion, as reflected in elevated stress. Practical implications Organisations should attend to peer-level social dynamics alongside workload and leadership factors. Monitoring toxic interpersonal patterns and intervening early may help protect shared psychological resources and sustain employee engagement and well-being. Originality/value This study reframes burnout as a socially transmitted, peer-driven process that develops through routine interactions with coworkers. By applying COR theory to peer-level DT exposure, this study extends burnout research beyond hierarchical explanations and highlights lateral social climates as a critical source of strain.