Developmental Psychology is no stranger to replication problems and actively combats them with widespread attention into new quantitative methods. Yet recent foundational studies still fail to replication (Davis-Kean & Ellis 2019). One exemplary case is Early Infant Theory of Mind in non-linguistic tasks (Rubio-Fernández 2019, Heyes 2014, Crivello & Poulin-Dubois 2018). I argue that the persistence of non-replications after extensive quantitative method modifications may be due to fundamental theoretical commitments in the field rather than measurement. As a result, I propose an intensive re-examination of theoretical foundations by Developmental Psychologist. I justify this turn by highlighting 4 common fundamental auxiliary assumptions (AA) that are poorly justified in Developmental research. 1) Cognition is computational, or rule based, 2) Failed task performance is a result of insufficient or missing computational capacities, 3) cognition as a phenomenon occurs only in the agent and is separate from the environment, 4) infants act upon rational motivates. These AA have their roots in the influence of GOFI and The Computational Theory of Mind on the Cognitive Revolution (See Lerner et al. 2007). I show a return to measurements is insufficient in addressing replication rates if there is not a deep investigation into unjustified AA. In order to overcome these shortcomings, I propose that the field needs to invest in interdisciplinary researchers, not educated only in Psychology, which conduct intensive interdisciplinary theoretical and empirical investigation into AA. The emphasis on interdisciplinary is meant to provide the proper conditions for a more objective Developmental Psychology. This was recognized by Eleanor and James Gibson and their lifelong interdisciplinary education and approach (which is constructed by ideas stemming from Phenomenology, Biology, Ecology, Geography, and Physics) to Cognitive and Developmental Psychology which stood alone without appealing to their contemporary unjustified AA (Gibson 1988, Gibson 2015). I thus argue that the approach adopted by the Gibson's, an interdisciplinary analysis of AA both theoretically and empirically, is the best option for the current state of Developmental Psychology if it wishes to overcoming replications issues in their field.

References

Crivello, C., & Poulin-Dubois, D. (2018). Infants' false belief understanding: A non-replication of the helping task. Cognitive Development, 46, 51–57.

Davis-Kean & Ellis (2019). An overview of issues in infant and developmental research for the creation of robust and replicable science. Infant Behavior and Development, 57, 101339.

Gibson, E. J. (1988). Exploratory Behavior in the Development of Perceiving, Acting, and the Acquiring of Knowledge. Annual Review of Psychology, 39(1), 1–42. 

Gibson, J. J. (2015). The ecological approach to visual perception. Psychology Press.

Heyes, C. (2014). Rich interpretations of infant behaviour are popular, but are they valid? A reply to Scott and Baillargeon. Developmental Science, 17(5), 665–666.

Lerner, R. M., Damon, W., & Overton, W. F. (2007). Developmental Psychology: Philosophy, Concepts, Methodology. In Handbook of child psychology (pp. 107–188). essay, Wiley.

Rubio-Fernández, P. (2019). Publication standards in infancy research: Three ways to make Violation-of-Expectation studies more reliable. Infant Behavior and Development, 54, 177–188.