Assessment of behavioral chaos with a focus on transitions in depression.

Abstract

This article is the second of three in a special section on chaos theory and psychological assessment. The purpose of this article is to address implications for the measurement of some unstable, transitional human behaviors. One early hallmark of behavioral assessment is the idiographic measurement of temporal, causal, and target factors (e.g., M. R. Goldfried & R. N. Kent, 1972). This is the same basic measurement approach used in chaos theory testing. In addition, behavioral theories have posited nonlinear relations among variables (e.g., J. D. Cone, 1981). However, theory testing often involves investigation of linear relations among episodic and averaged indexes of the variables (e.g., M. J. Marr, 1989). The study of unstable behaviors and chaotic transitions could revive the use of unaveraged single-subject, time series measurement approaches. A rationale for a subtype of chaotic depression (e.g., L. Glass & M. C. Mackey, 1988) and its measurement is offered