De Houwer, J. (2011). Why the cognitive approach in psychology would profit from a functional approach and vice versa. Perspectives on Psychological Science, 6(2), 202-209.
Cognitively oriented psychologists often define behavioral effects in terms of mental constructs (e.g., classical conditioning as a change in behavior that is due to the formation of associations in memory) and thus effectively treat those effects as proxies for mental constructs. This practice can, however, hamper scientific progress. I argue that if psychologists would consistently define behavioral effects onl in terms of the causal impact of elements in the environment (e.g., classical conditioning as a change in behavior that is due to the pairing of stimuli), they would adopt a functional approach that not only reveals the environmental cuases of behavior but also optimizes cognitive research. The cognitive approach in turn strengthens the functional approach by facilitating the discovery of new causal relations between the environment and behavior. I thus propose a funcional-cognitive framework for reserach in psychology that capitalizes on the mutually supportive nature of the functional and cognitive approaches in psychology.