The bitter truth about sugar and willpower

Dual-process theories of higher order cognition (DPTs) have been enjoying much success, particularly since Kahneman’s 2002 Nobel prize address and recent book Thinking, Fast and Slow (2009). Historically, DPTs have attempted to provide a conceptual framework that helps classify and predict differences in patterns of behavior found under some circumstances and not others in a host of reasoning, judgment, and decision-making tasks. As evidence has changed and techniques for examining behavior have moved on, so too have DPTs. Killing two birds with one stone, Evans and Stanovich (2013, this issue) respond to five main criticisms of DPTs. Along with addressing each criticism in turn, they set out to clarify the essential defining characteristics that distinguish one form of higher order cognition from the other. The aim of this commentary is to consider the defining characteristics of Type 1 and Type 2 processing that have been proposed and to suggest that the evidence can be taken to support quantitative differences rather than qualitatively distinct processes.