Getting from states to traits: Whole Trait Theory’s explanatory and developmental engine

Whole Trait Theory (WTT) has emerged as a prominent account of personality dynamics over the last decade. Building on the density distributions conceptualization of personality trait manifestation, WTT provides an account of how Big 5-relevant behavior systematically varies across contexts while exhibiting long-term stability. However, one possible criticism of WTT relates to (a) the specific nature of the explanatory mechanisms underlying the density distribution of personality trait manifestations and (b) how these mechanisms undergird short- and long-term change. In this target article, we clarify our definition of a trait, refine and elaborate the description of constrained accretion, discuss the role of biology and physiology in the development of traits, identify possible kinds of mechanisms that produce density distributions, and discuss how WTT explains personality development.