Is there a poverty of the stimulus? Lessons from developmental systems.

The poverty-of-stimulus (POS) argument, the proposition that the environment is insufficiently structured (i.e., “impoverished”) to completely account for the ontogeny of organismal knowledge, has been used to motivate theories of innate knowledge in the cognitive, linguistic, and developmental sciences. While in recent decades the POS argument has attracted a number of criticisms and defenses, previous examinations of the POS argument have largely addressed linear aspects of development— developmental experiences that are related in an obvious manner to a particular developmental outcome. Research on developmental systems, however, illustrates that both linear and non-linear (i.e., non-obvious) experiences shape the ontogeny of organismal knowledge. In the current review, we, first, introduce the POS argument and briefly summarize its theoretical impact in the cognitive sciences. Then, we introduce the notions of developmental linearities and non-linearities by reviewing seminal work on non-human-animal models of ontogeny from ethology and comparative psychology. Finally, we discuss the implications of this work on the POS argument: we conclude that resilient, species-typical outcomes which, superficially, would appear to require a form of “innate” knowledge, may, ultimately, reflect non-obvious forms of experience that occur within a broader, reoccurring developmental system.