Hardiness as a Predictor of Human Performance in High-Demand Military Environments: A Narrative Review

Narrative review on psychological hardiness as a predictor of human performance in high-demand military contexts (2015–2025). Databases: PubMed, Scopus, Web of Science. No language/type restrictions. Screening by title/abstract and full text; transparency ensured via decision memos and exclusion codes (E1–E6). Minimal extraction sheet (Author/Year; Country/Force/Context; n; Hardiness instrument; Primary outcome; Key metric; Direction; Note). Narrative, theme-based synthesis (persistence, selection/leadership, HRV/cortisol). OSF hosts search strings, screening logs, and data extraction templates.