Understanding willingness to fight: Motivational and personality predictors in Ukrainian military personnel with and without combat experience

This study examined psychological predictors of willingness to fight among Ukrainian service members during the ongoing war and whether associations vary by combat experience. A cross-sectional sample of <i>N</i> = 172 personnel (121 combat-experienced; 51 non-combat) completed measures of motivation, Big Five traits, conflict-handling styles, communication skills, and professional hardiness. Descriptive group contrasts emphasized effect sizes (Welch's t with Hedges' g or rank-biserial r where appropriate). Bivariate Pearson correlations (Fisher-z CIs, false-discovery-rate adjustment for the set with willingness) and a theory-driven hierarchical regression with heteroskedasticity-robust standard errors were used; moderation was tested with Combat × predictor interactions. Combat-experienced personnel reported higher willingness to fight (g = .48, 95% CI [.15, .81]) and small-to-moderate differences on several traits (e.g. higher Extraversion, Conscientiousness, Competing; lower Avoiding). Zero-order correlations with willingness were strongest for Intrinsic motivation (<i>r</i> = .51), Professional control (<i>r</i> = .40), Professional commitment (<i>r</i> = .39), Openness (<i>r</i> = .37), and Challenge acceptance (<i>r</i> = .34). The final model explained R2 = .49 (adj. R2 = .41); two predictors made unique contributions to willingness to fight: combat experience (β = .43, 95% CI [.10, .77], <i>p</i> = .011) and Intrinsic motivation (β = .35, 95% CI [.17, .52], <i>p</i> < .001). A planned Avoiding × Combat interaction was significant (β = .49, <i>p</i> = .019) with opposite-direction but individually non-significant simple slopes. Findings underscore Intrinsic motivation as the central psychological predictor of willingness to fight, with combat experience providing an additional independent contribution and interpersonal tendencies showing experience-contingent nuances.