The focus of much temperament research has been on the description of individual differences at various points of time in infancy and childhood (e.g., see Goldsmith et al., 1987). When longitudinal data on temperament have been analyzed, the focus has been primarily on stability of measurement and secondarily on the links between early assessments of temperament and later measures of psychosocial functioning. Very few studies have examined whether and how temperament measures may change over childhood (see Matheny, 1984; Maziade, Cote, Bernier, Boutin, & Thivierge, 1989 for exceptions to this generalization). Very little is known about specific contextual factors that might influence temperamental change. Previous research suggests that long-standing environmental influences may be influential in changing temperamental dimensions, and that changes can also be directed by genes (i.e., maturation, see, for example, Matheny & Dolan, 1975). Basic data on change, however, are sparse. In this chapter we examine individual and group patterns of change in temperament for children who were aged 4 years at the beginning of our study and 7 years at the end. We then examine how individual change scores for one selected dimension of temperament (Persistence) are affected by variables reflecting parenting, marriage, and family contexts, and examine how change in Persistence is also moderated over time by changes in other temperament dimensions.