Exploratory validation of the IWBMC™ spirit and will scale: Internal consistency, factor structure, and construct validity in measuring psychological resilience

Abstract

The Interpersonal Whole-Brain Model of Care® (IWBMC™) conceptualizes psychological resilience through Spirit (Identity, connection, emotional regulation) and Will (Growth-oriented persistence and cognition). This exploratory validation examined the 60-item IWBMC Spirit & Will Assessment Scale in 207 community participants and assessed internal consistency, factor structure, and preliminary construct validity. Parallel analysis suggested six factors; however, because a sixth factor had fewer than three items with clear primary loadings, we interpreted a 5-factor solution. Total scale reliability was excellent (α = 0.95). Domain-level reliability ranged from acceptable to good: Core Identity (α = 0.88), Social Connection (α = 0.80), Emotional Acceptance & Regulation (α = 0.75), Emotional Capacity for Growth & Safety (α = 0.87), and Cognitive Mindset (α = 0.85) met standards.  Key findings include: (a) Will domains (SW4, SW5) merged empirically, suggesting a unified rather than a dual-component structure; (b) safety-related items clustered distinctly; and (c) Social Connection items dispersed across factors. Significant sex differences emerged on Will-related domains, with males scoring higher (SW4, SW5, and Will composite; d = 0.30-0.39). Two small but significant race/ethnicity effects emerged for SW5 and the Will composite (η² = 0.062-0.067), driven primarily by lower scores among participants preferring not to disclose their race/ethnicity. No significant age differences were found (all ps > 0.10, all η²  < 0.037). These results provide data-driven guidance for refining domain boundaries while confirming the domain’s overall utility. The scale demonstrates promising psychometric properties and requires targeted refinement before confirmatory validation.