From bystanders to allies: a narrative review of witnessing age discrimination in age-diverse workplaces

Purpose This paper aims to explore how witnessed ageism influences observer responses, focusing on the development of age group allegiance. Using social cognitive and social identity theories, we position negative affect as the link between witnessed ageism and age-group allegiance, moderated by age diversity climate. This model explains how discrimination spreads through social observation in organizations. Design/methodology/approach We conducted a narrative literature review synthesizing 63 peer-reviewed studies on workplace ageism, bystander responses and identity processes. This approach enables conceptual model development for an emerging research area where heterogeneous methodologies preclude systematic review protocols. Findings Our conceptual model proposes that witnessed ageism relates positively to age group allegiance, mediated by negative affect and moderated by age diversity climate. Different forms of ageism – competence-, adaptability-, socio-emotional- and resource-based – trigger distinct social categorization processes. Research limitations/implications The model primarily examines younger employees observing ageism against older workers. Future research should examine bidirectional ageism, additional mediators and cross-cultural differences. The study supports further research on the social transmission of workplace discrimination. Originality/value To the best of the authors' knowledge, this is one of the first conceptual papers to introduce a witness-centered perspective that moves beyond traditional victim–perpetrator models. By integrating cognitive, emotional, and identity-based perspectives through an uncertainty-reduction lens, it offers novel insights into how observed ageism reinforces organizational age divisions through in-group belonging rather than out-group hostility (Brewer, 1999) – explaining why discrimination persists even among empathetic observers.