Overspecification – An Overlooked but Essential Aspect of Psychological Theory Development

Abstract: In the wake of the replication crisis, it has been argued that many psychological theories do not sufficiently specify under which boundary conditions a hypothesized empirical effect occurs versus does not occur, which may explain why conceptual replications are sometimes unsuccessful. This reasoning implies that one path toward theory building is to identify all boundary conditions and to integrate them into the respective theory underlying the effect. In this article, we argue that identifying boundary conditions is undoubtedly worthwhile, but it comes with the risk of overspecifying theories. Overspecification occurs when certain assumptions of a hypothesis or theory can be dropped without noticeable loss in explanatory power. We argue that identifying boundary conditions for an effect to occur can be fruitfully combined with testing for overspecification of a hypothesis or theory. Such a combined strategy can improve cumulative theory building and, thus, increase the efficiency and integrability of psychological research.