Differential Structural Equation Modeling of Intraindividual Variability

Recent advances in modeling and analysis have enabled statistical tests of dynamical systems based theories for behavioral phenomena. The use of statistical models to test proposed dynamical or self–regulating explanations of intraindividual variability has the potential to lead to new and more tightly focused understandings of cognitive, developmental and social systems. This chapter provides an introduction to the use of differential structural equation models (dSEM) to fit data from repeated observations of individuals: intraindividual variability. Example data from an experiment in the development of postural control are analyzed in order to give a practical demonstration of these methods. Models are fit to individual trials in a postural control experiment and the resulting estimated parameters are analyzed using a random coefficients approach to elucidate development in the dynamics of intraindividual variability.