Elephants and Horses

Things change. Sometimes they change gradually, sometimes dramatically. The prevailing concept of change in psychology consists of only one form of change, linear change, which is simply undifferentiated, and with the assumption that outcomes are proportional to inputs in a straightforward manner. The overreliance among psychologists and others on the general linear model as a statistical tool for depicting change has only served to reinforce this monochrome conceptualization of change. Perhaps the most significant deviations from the concept of linear change are the concepts of equilibrium and randomness. For most intents and purposes, the concept of equilibrium has been used to describe places or times when change stops occurring. Randomness suggests that the changes are unpredictable and not explicable by any known concepts or predictors.

Nonlinear dynamical systems (NDS) theory significantly enriches our capability to conceptualize change, and it provides a rich array of constructs that describe many types of change. The concept of equilibrium is no longer specific enough to describe either the change or the events that surround the point where change stops. The new constructs are the attractors, bifurcations, chaos, fractals, self-organization, and catastrophes. As this chapter explains, each of these constructs contains several more, including those associated with the “complexity” of a system. Importantly, change is not proportional to inputs. Large inputs sometimes produce small results, and a small input at the right time can produce a dramatic result.

Psychology is not the first science to break out of the linear rut.