Personality-Related Traits and Psychological and Cognitive Outcomes Under High-Altitude Hypoxia: A Trait-Process-Outcome Framework.

High-altitude hypoxia is associated with sleep disruption, affective fluctuation, and changes in cognitive performance, yet prior findings remain markedly heterogeneous in both direction and magnitude. To clarify this variability, this structured narrative review synthesizes evidence from systematic reviews, meta-analyses, and key empirical studies on psychological and cognitive adaptation to high-altitude hypoxia, with a particular focus on personality and related traits. The review is organized along three axes: exposure context and characterization (real-altitude field/residential exposure, hypobaric chambers, normobaric hypoxia, expedition settings, and dose alignment), exposure duration and time course, and outcome domains spanning sleep/fatigue, affective adaptation, and cognitive performance. Across the literature, cognitive effects appear domain-specific and strongly conditioned by exposure dose, temporal stage, and task characteristics, whereas sleep disturbance during the early acclimatization period emerges as one of the more consistent findings and appears closely intertwined with anxiety-related responses. Although direct personality-related evidence remains limited and uneven, the available findings can be organized into a testable trait-process-outcome framework that distinguishes candidate associations with relatively more direct evidence from mechanism-informed hypotheses. Neuroticism/emotional stability and anxiety-related traits have received comparatively more direct empirical investigation than other personality domains, but the available evidence is insufficient to regard them as established predictors of high-altitude adaptation. The roles of conscientiousness, resilience/hardiness, extraversion, agreeableness, and openness remain more tentative and are better treated as targets for prospective testing. We therefore propose that personality-related dispositions may influence adaptation-relevant outcomes through candidate processes involving threat appraisal, coping, resource regulation, and social interaction. We conclude that future research should strengthen exposure dose characterization, specify the boundary conditions for generalizing across real-altitude, hypobaric-chamber, normobaric hypoxia, and expedition settings, and adopt longitudinal, multilevel, and ecologically valid designs to test personality-related pathways more rigorously.