Servant Leadership and Employee Organisational Citizenship Behaviour in Nigerian Higher Education Institutions: The Mediating Effect of Psychological Safety

This study examines the relationship between servant leadership and employee organisational citizenship behaviour (OCB) in Nigerian higher education institutions, proposing psychological safety as a mediating mechanism. Nigerian universities are under profound pressure to improve educational quality and institutional effectiveness, and the leadership behaviours of department heads and faculty deans are increasingly recognised as critical determinants of the discretionary contributions staff are willing to make beyond their formal roles. The study draws on a sample of 248 academic staff from eight universities across the South West, North East, and South South geopolitical zones, selected through multistage stratified sampling. Instruments include the Servant Leadership Survey adapted for academic contexts, Edmondson's Team Psychological Safety Scale, and the Organ OCB Questionnaire. Social Exchange Theory and Self-Determination Theory provide the theoretical grounding. PLS-SEM with bootstrap confidence intervals is employed for hypothesis testing. Findings confirm that servant leadership significantly and positively predicts OCB across all five OCB dimensions. Psychological safety significantly mediates the servant leadership-OCB relationship, explaining 54 percent of the total effect. The mediation is strongest for the altruism and civic virtue OCB dimensions, suggesting that psychologically safe climates particularly enable helping and participatory citizenship. The study also finds that servant leadership effects are stronger in departments with higher staff-to-student ratios, suggesting workload context moderates the leadership-behaviour relationship. Recommendations include servant leadership competency training for academic managers and psychological safety climate assessments. Keywords: Servant Leadership, OCB, Psychological Safety, Higher Education, Nigeria.