A broader approach to research in human development is proposed that focuses on the progressive accommodation, throughout the life span,

between the growing human organism and the changing

environments in which it actually lives and grows.  The latter include not only the immediate settings containing the developing person but also the larger social contexts, both formal and informal, in which

these settings are embedded. In terms of method, the approach emphasizes the use of rigorous designed experiments, both naturalistic and contrived, beginning in the early stages of the research process. The changing relation between person and environment is conceived in systems terms. 

 As argued elsewhere (Bronfenbrenner, 1974), the emphasis on rigor has led to experiments that are elegantly designed but often limited in scope. This limitation derives from the fact that many of these experiments involve situations that are unfamiliar, artificial, and short-lived and that call for unusual behaviors that are difficult to generalize to other settings. From this perspective, it can be said that much of contemporary developmental psychology is the science of the strange behavior of children in strange situations with strange adults for the briefest possible periods of time.