Activating moral knowledge or suppressing deviance? The interactive effects of honesty-humility and ethical leadership on workplace deviance

• Explores ethical leadership as a potential activator and suppressor of Honesty-Humility (HH) • Offers a “trait-activation-suppression” framework for HH and deviance. • Tests dual mechanisms: moral knowledge (MK) activation & deviance suppression (DS) • DS perceptions occur across HH levels but have minimal impact on reducing deviance. • Ethical leadership influences the HH-deviance relationship through MK over deterrence mechanisms. Honesty-Humility (HH), the primary ethics-related dimension in the HEXACO personality model, is crucial for understanding workplace ethical conduct. We draw on and extend trait activation theory to encompass both activation and suppression mechanisms, proposing that ethical leadership activates and deactivates tendencies consistent with high and low HH, respectively, to shape the relationship between HH and workplace deviance. Across three samples, including a three-wave multi-source survey, we show ethical leadership moderates the HH-workplace deviance relationship. Our findings reveal a nuanced view of this dual-process model: ethical leadership primarily enhances the relationship between employee HH and moral knowledge, which in turn lowers deviance, whereas its effect on perceived deviance suppression—though present—does not translate as robustly into behavioral outcomes. Results indicate that ethical leadership is most effective at shaping the personality-deviance relationship by activating latent ethical tendencies, contributing to theories of trait activation and workplace deviance antecedents.