Mind & Society

, Volume 11, Issue 1, pp 15-26

First online:

Dual processes, probabilities, and cognitive architecture

  • Mike OaksfordAffiliated withDepartment of Psychological Sciences, Birkbeck College, University of London Email author 
  • , Nick ChaterAffiliated withBehavioural Science Group, Warwick Business School, University of Warwick

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It has been argued that dual process theories are not consistent with Oaksford and Chater’s probabilistic approach to human reasoning (Oaksford and Chater in Psychol Rev 101:608–631, 1994, 2007; Oaksford et al. 2000), which has been characterised as a “single-level probabilistic treatment[s]” (Evans 2007). In this paper, it is argued that this characterisation conflates levels of computational explanation. The probabilistic approach is a computational level theory which is consistent with theories of general cognitive architecture that invoke a WM system and an LTM system. That is, it is a single function dual process theory which is consistent with dual process theories like Evans’ (2007) that use probability logic (Adams 1998) as an account of analytic processes. This approach contrasts with dual process theories which propose an analytic system that respects standard binary truth functional logic (Heit and Rotello in J Exp Psychol Learn 36:805–812, 2010; Klauer et al. in J Exp Psychol Learn 36:298–323, 2010; Rips in Psychol Sci 12:29–134, 2001, 2002; Stanovich in Behav Brain Sci 23:645–726, 2000, 2011). The problems noted for this latter approach by both Evans Psychol Bull 128:978–996, (2002, 2007) and Oaksford and Chater (Mind Lang 6:1–38, 1991, 1998, 2007) due to the defeasibility of everyday reasoning are rehearsed. Oaksford and Chater’s (2010) dual systems implementation of their probabilistic approach is then outlined and its implications discussed. In particular, the nature of cognitive decoupling operations are discussed and a Panglossian probabilistic position developed that can explain both modal and non-modal responses and correlations with IQ in reasoning tasks. It is concluded that a single function probabilistic approach is as compatible with the evidence supporting a dual systems theory.


Reasoning Probabilities Dual processes Cognitive architecture Defeasibility Individual differences Panglosian Meliorist