Group identity mainly boosts discretionary extra-role effort, not required performance

Evidence

According to van Knippenberg (2000), when the groups’ interests are aimed at work performance, identification with that group will motivate the individuals toward higher work performance. Van Knippenberg differentiates between task performance and contextual performance. Task performance involves role requirements, and contextual performance refers to such extra-role activities that may benefit the performance of the work unit as a whole, such as those consistent with organizational citizenship behavior (OCB). OCB is an extra-role behavior that benefits the organization but is not required for the job (Bateman & Organ, 1983). The effects of social identity are more likely to be apparent on contextual performance rather than task performance (van Knippenberg, 2000), indicating a potential relationship between social identity and individuals’ OCB (e.g., Christ, van Dick, Wagner, & Stellmacher, 2003). — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 1752

Categorization

• XREF: Mechanism parallel to prejudice: identification expresses itself in discretionary behaviors (slights, microaggressions, helping co-ethnics) rather than formally required ones — usable contrast for how ingroup bias operates outside formal roles.
• corroborated: 2 independent passages support this claim — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 1752