Behavioral and Brain Sciences

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Behavioral and Brain Sciences (2009), 32:530-531 Cambridge University Press
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Open Peer Commentary

Are delusions biologically adaptive? Salvaging the doxastic shear pin

Aaron L. Misharaa1a2 and Phil Corletta1a3

a1 Department of Psychiatry, Brain Mapping Unit and Behavioural and Clinical Neurosciences Institute, University of Cambridge, School of Clinical Medicine, and Addenbrooke's Hospital, Cambridge CB2 2QQ, United Kingdom
a2 Department of Psychiatry, Clinical Neuroscience Research Unit, Yale University School of Medicine, Connecticut Mental Health Center, New Haven, CT 06519
a3 Department of Psychiatry, Abraham Ribicoff Research Facilities, Yale University School of Medicine, Connecticut Mental Health Center, New Haven, CT 06519.
Article author query
mishara al [PubMed]  [Google Scholar]
corlett p [PubMed]  [Google Scholar]


In their target article, McKay & Dennett (M&D) conclude that only “positive illusions” are adaptive misbeliefs. Relying on overly strict conceptual schisms (deficit vs. motivational, functional vs. organic, perception vs. belief), they prematurely discount delusions as biologically adaptive. In contrast to their view that “motivation” plays a psychological but not a biological function in a two-factor model of the forming and maintenance of delusions, we propose a single impairment in prediction-error–driven (i.e., motivational) learning in three stages in which delusions play a biologically adaptive role.

The evolution of misbelief Ryan T. McKay and Daniel C. Dennett Institute for Empirical Research in Economics, University of Zurich, Zurich 8006, Switzerland; and Centre for Anthropology and Mind, University of Oxford, Oxford OX2 6PE, United Kingdom; The Center for Cognitive Studies, Tufts University, Medford, MA 02155-7059