Measuring Adult Development and Exploring its Relationship to Leadership: Parallel Journeys through the Lens of Constructive-Developmental Theory

Abstract

Despite a great proliferation of theories and research over the last century – close to 50,000 references from a recent search of PsycINFO alone – researchers continue to argue that less is known about leadership than in any comparative field. This thesis proposes an adult development approach to leadership; one that is focused on constructive-developmental theory (Kegan, 1982; 1994), and one that has the potential to address questions earlier leadership theories have been unable to answer. A constructive-developmental approach is not new, yet this theory has sat almost unnoticed on the fringe of the leadership literature for 40 years. As such, the aim of this thesis is twofold: first, to garner insights from an investigation of the evidence base at the intersection of adult development and leadership; and second, to address gaps in the measurement of adult development that might help to bring this field into the mainstream of leadership research. Study 1, a systematic review, and the first of its kind in this field, revealed a broad empirical evidence base for the importance of constructive-developmental theory to the study and practice of leadership. Study 2 through to Study 5 begin the development of a new measure of adult development. This measure shows promise to be psychometrically sound, practical, and cost effective – thus, it has the potential to enable research in ways that the current complex and costly methods do not. Study 6, a qualitative leader cohort study, provides a unique perspective on the perceptions and experiences of eight leaders at different stages of adult development. The findings in this thesis support the proposition that adult development and leadership are parallel journeys. Furthermore, this research suggests a constructive-developmental framework offers an illuminating and integrated approach to leadership that may both account for leader effectiveness, and accommodate earlier theories of leadership.