We Are All Dynamic Systems: Unifying Psychology’s Subdisciplines With a Developmental Perspective

Psychology has been a relatively disunified discipline since its inception, partly owing to the historical context in which it arose as a science. The interdisciplinary field of developmental science can potentially overcome this fragmentation. Specifically, the Developmental Systems (DS) approach recognizes that individuals, together with their contexts, constitute self-organizing, dynamic, complex systems best characterized by the processes that transpire when system components work together to build psychological attributes. This approach holds that these attributes emerge during development in ways that depend on spatial and temporal (i.e., historical) relations among system components. DNA works in collaboration with other factors in its local environment, so genetic determinism can be rejected; psychological traits cannot be predicted from genetic information alone. Research on the epigenetic control of gene expression has bolstered this insight, revealing how experiences influence genetic activity and, ultimately, behavior. Behavioral epigenetics likely bears on all psychological phenomena, putting it in a position to help unify the behavioral sciences. The DS perspective encourages skepticism of constructs that assign static traits to individuals and of tests that rely on genetic information alone to predict developmental outcomes. Because all characteristics develop—and because individuals are cohesive, highly integrated systems—psychology’s unification is an attainable goal that will be advanced by adopting this perspective.