The ways school headteachers/principals in England at different stages of adult ego development work with organisational complexity.

This article examines how school headteachers/principals (HT/Ps) in England at different stages of adult ego development (AED)—assessed via the Washington University Sentence Completion Test (WUSCT)—make sense of and respond to the organisational complexity of their schools, particularly in relation to "wicked problems," which are complex, ambiguous, and evolving issues without clear solutions. The study identifies three AED stages among HT/Ps: self-aware, conscientious, and individualist, each demonstrating distinct approaches to complexity. HT/Ps at the self-aware stage tend to simplify problems, rely on hard data and policies, and respond rapidly without acknowledging emerging factors; those at the conscientious stage recognize multiple factors and seek predictability through detailed planning but ultimately narrow their focus to key causes; while individualist-stage HT/Ps embrace complexity fully, engage collaboratively with a broad range of stakeholders, tolerate ambiguity, and actively recognize emergent factors. The findings reveal a developmental trend of increasing complexity acknowledgement, tolerance for ambiguity, and recognition of emergence across these stages, suggesting that AED stage influences HT/P effectiveness and has implications for leadership development and support in educational settings.