A critique of the principle of cognitive simplicity in comparative cognition

Abstract

A widespread assumption in experimental comparative (animal) cognition is that, barring compelling evidence to the contrary, the default hypothesis should postulate the simplest cognitive ontology (mechanism, process, or structure) consistent with the animal’s behavior. I call this assumption the principle of cognitive simplicity (PoCS). In this essay, I show that PoCS is pervasive but unjustified: a blanket preference for the simplest cognitive ontology is not justified by any of the available arguments. Moreover, without a clear sense of how cognitive ontologies are to be carved up at the joints—and which tools are appropriate for the job—PoCS rests on shaky conceptual ground.