Empowering Confidence before Authority: Principal Humble Leadership, Role Breadth Self-efficacy, Teacher Autonomy, and Proactive Work Behavior in Taiwanese Secondary Schools

Abstract Policy reforms expand teachers’ formal authority, but the gap between policy and practice, treated here as a contextual condition rather than an empirically estimated discrepancy, does not necessarily occur because of structural conditions for implementation alone; the psychological responses of teachers also play a role. This study specifically examines whether role breadth self-efficacy (RBSE), representing perceived capability and role legitimacy, and perceived teacher autonomy, representing experienced discretion, function as distinct parallel mediators linking principal humble leadership to teachers’ proactive work behavior (PWB) during Taiwan’s 12-year Basic Education reform (the “108 Curriculum”). The culturally extended four-factor principal humble leadership scale developed for this study includes two Confucian-based factors (Li Xian [禮賢] and Jin Shen [謹慎]) along with two factors from the original three-factor Western model. The principal humble leadership scale demonstrated strong psychometric properties (14 items; Cronbach’s alpha coefficient = .968; Comparative Fit Index = .998; Root Mean Square Error of Approximation = .055), and Heterotrait–monotrait (HTMT) ratios among its factors ranged from .789 to .874 (all below .90), with bootstrapped 95% confidence intervals excluding 1.00, supporting the empirical distinctiveness and non-redundancy of the Confucian dimensions. Using social cognitive theory and self-determination theory, a mediated relationship model was tested to determine whether role breadth self-efficacy (RBSE) and perceived teacher autonomy would mediate the relationship between principals’ humble leadership and teachers PWB. A survey instrument was used to collect data from 616 junior/senior high school teachers in Northern Taiwan. Data analysis was conducted using the SPSS PROCESS macro (Model 4) with bias-corrected bootstrap. The results showed that principal humble leadership was positively associated with teacher PWB, with role breadth self-efficacy as the primary mediator, accounting for 53.07% of the total effect of principal humble leadership on teacher PWB, and perceived teacher autonomy as the second most important mediator (accounting for 8.52% of the total effect). A formal pairwise bootstrap contrast confirmed that the RBSE pathway was significantly stronger than the autonomy pathway, with the difference between the two specific indirect effects (.0915) having a 95% confidence interval that excluded zero ([.045, .144]). Additionally, subdimension analyses found that role breadth self-efficacy was the only mediator significantly associated with high visibility/hierarchically challenging teacher behaviors (e.g., taking charge, giving voice), reflecting a statistical pattern consistent with full mediation through role breadth self-efficacy, and that both mediators accounted for a portion of the relationship between principal humble leadership and low visibility/less hierarchically challenging behaviors (e.g., individual innovation, preventing problems), with the direct effects remaining significant (partial mediation) and with the two indirect pathways statistically indistinguishable for these lower-visibility behaviors (role breadth self-efficacy larger only in point estimate for individual innovation). Overall, these results support a risk-based, culturally sensitive view of how humble leadership fosters the capability beliefs (role breadth self-efficacy) that convert commonly held, policy-granted structural autonomy into teachers’ proactive work behavior, with implications for principal development and educational reform in Confucian-heritage, high-power-distance school systems similar to the sampled setting, pending cross-cultural validation across the wider Asia–Pacific region.