Abstract— The nativist–empiricist debate and the nativist commitment to the idea of core knowledge and endowments that exist without relevant postnatal experience continue to distract attention from the reality of developmental systems. The developmental systems approach embraces the concept of epigenesis, that is, the view that development emerges via cascades of interactions across multiple levels of causation, from genes to environments. This view is rooted in a broader interpretation of experience and an appreciation for the nonobvious nature of development. This systems approach is illustrated here with examples from studies of imprinting, spatial cognition, and language development, revealing the inadequacies of the nativist–empiricist debate and the inconvenient truths of development. Developmental scientists should no longer abide the nativist–empiricist debate and nativists’ ungrounded focus on origins. Rather, the future lies in grounding science in contemporary theory and developmental process.