Development is a fact of life. Throughout the lifespan process, we meet challenges and tasks that are specific to an age. Throughout life critical biological, psychological and sociological factors affect the developmental process. For example, the production of speech emerges in the first three years of life. When speech occurs without significant concerns, parents breathe a collective sigh of relief. However, if a child is not talking by age three, this may signal developmental concerns. These kinds of developmental signposts occur throughout the lifespan. In the first couple years of life the influence of biological, psychological and sociological factors are equally strong and somewhat predictable. As we grow up, the biological factors seem to be less dramatic.
Inherent in the biopsychosocial perspective of development is the belief that development occurs in a dynamic, yet predictable and orderly fashion and that styles of thinking, sociability, and behavior can be associated with a specific ages throughout the lifespan.