Subtracting “ought” from “is”: Descriptivism versus normativism in the study of human thinking
Shira Elqayam and Jonathan Evans
Abstract: We propose a critique of normativism, deﬁned as the idea that human thinking reﬂects a normative system against which it should be measured and judged. We analyze the methodological problems associated with normativism, proposing that it invites the controversial “is-ought” inference, much contested in the philosophical literature. This problem is triggered when there are competing normative accounts (the arbitration problem), as empirical evidence can help arbitrate between pescriptive theories, but not between normative systems. Drawing on linguistics as a model, we propose that a clear distinction between normative systems and competence theories is essential, arguing that equating them invites an “is-ought” inference: to wit, supporting normative “ought” theories with empirical “is” evidence. We analyze in detail two research programmes with normativist features – Oaksford and Chater’s rational analysis and Stanovich and West’s individual differences approach – demonstrating how, in each case, equating norm and competence leads to an is-ought inference. Normativism triggers a host of research biases in the psychology of reasoning and decision making: focusing on untrained participants and novel problems, analyzing psychological processes in terms of their normative correlates, and neglecting philosophically signiﬁcant paradigms when they do not supply clear standards for normative judgement. For example, in a dual-process framework, normativism can lead to a fallacious “ought-is” inference, in which normative responses are taken as diagnostic of analytic reasoning. We propose that little can be gained from normativism that cannot be achieved by descriptivist computational-level analysis, illustrating our position with Hypothetical Thinking Theory and the theory of the suppositional conditional. We conclude that descriptivism is a viable option, and that theories of higher mental processing would be better off freed from normative considerations.
Keywords: Bayesianism; competence; computational-level analysis; descriptivism; is-ought inference; logicism; normative systems; normativism; rational analysis; rationality; research bias; understanding/acceptance principle
It's a very interesting paper, which raises in particular the question of the status of formal models as normative models for human reasoning, and this is, I believe, highly relevant for the M-Phi community. The list of commentaries includes many philosophers and philosophically-inclined psychologists, such as: Dora Achourioti, Andy Fugard , Keith Stenning, Igor Douven, Stephen Stich, Niki Pfeifer, Nick Chater and Mike Oaksford, Joelle Proust, Gerhard Schurz, Keith Stanovich, and myself, among many others.