Understanding the mind of the modern workers through the short Dark Tetrad and Light Triad traits: The good, the bad and the situational

Research on socially aversive personality in organisations has largely centred on the Dark Triad, with comparatively limited attention to everyday sadism (Short Dark Tetrad; SD4) and the countervailing influence of Light Triad traits (LTT). This narrow focus constrains theoretical development in understanding how aversive and prosocial dispositions jointly shape workplace behaviour. Addressing this gap, we integrate Trait Activation Theory and Person–Situation Interactionism with Generational Cohort Theory and HEXACO's Honesty–Humility dimension to develop a multilevel perspective on dark/light trait expression. We conducted a systematic literature review following PRISMA guidelines across five major databases, synthesising 42 manuscripts published between 2020 and 2025. Using a PICO-informed framework, we organise findings across three core domains of organisational behaviour: deviant vs citizenship behaviour, work engagement, and leadership and organisational change. Our synthesis reveals that dark/light traits exert paradoxical effects. Machiavellianism is associated with unethical conduct but may enhance effectiveness under conditions of environmental uncertainty, whereas Kantian orientations promote cooperation but may constrain competitive responsiveness. Narcissistic and psychopathic traits are linked to short-term engagement, while humanism and faith in humanity underpin more prosocial forms of engagement. These patterns highlight a fundamental strain in how engagement and effectiveness are conceptualised within organisations. We further show that generational cohort differences shape the activation and expression of SD4/LTT, suggesting that intergenerational dynamics represent an underexplored boundary condition in personality–behaviour relationships. The study contributes to organisational behaviour research by clarifying when and why aversive vs prosocial traits emerge and the consequences of their emergence. Practical implications include designing organisational contexts that attenuate maladaptive trait activation while promoting sustainable engagement and ethical conduct.