This study develops a set of theoretically grounded propositions that can serve as a basis for future research on team backup behaviours through a systematic literature review. Backup behaviours are defined as the anticipation of teammates’ needs, provision of assistance, and redistribution of workload. Within prominent team effectiveness frameworks, particularly IMOI models and conceptualizations of core team processes such as the “Big Five” of teamwork, backup behaviours are regarded as a central process through which inputs are translated into effective team functioning. However, empirical evidence suggests this process may also impose cognitive and resource-related costs, potentially hindering performance under certain conditions. Despite its theoretical prominence, findings on its antecedents, outcomes and boundary conditions remain fragmented. To address this gap, the review synthesizes empirical evidence on (1) the antecedents of backup behaviours, (2) their effects on team outcomes, and (3) the mediating and moderating mechanisms shaping these relationships. Following a pre-registered protocol, studies published in peer-reviewed journals indexed in Scopus and Web of Science (1990-January 2026) were considered. A total of 210 records were screened (title and abstract), with 41 articles assessed in full text and 5 additional studies identified through manual search, resulting in a final sample of 26 empirical studies. Screening and data extraction were conducted using a human-AI reviewer combination, with disagreements resolved by a third reviewer. As analyses are ongoing, this review will advance an integrative framework and develop theoretically grounded propositions to clarify when and how backup behaviours enhance or hinder team effectiveness, contributing to theory development and future research in team contexts.

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