ABSTRACT
In 50 years, psychology has advanced as a science and new theoretical approaches to human development have been presented. This chapter reviews what actually happened during these years to the conceptual constructs of the two-dimensional model as the framework for the study of children's socioemotional behavior. It shows how to describe developmental processes within the two-dimensional model. Amendments that have been made to the model have concerned theoretical constructs, but not the basic hypotheses on individual differences. Emotional regulation helps to maintain internal arousal within a manageable, optimal performance range, whereas behavior regulation helps one to adjust one's reactions to external circumstances. The chapter analyses an individual's situation-specific behavior to include a description of individuals' characteristic behaviors. In the context of writing the synthesis of the longitudinal study, it necessary to amend the two-dimensional framework model by adding a developmental perspective to it.
