Behavioral and Brain Sciences

Authors' Response
Commentary on Stanovich, K. E. and West, R. F. “Individual differences in reasoning: Implications for the rationality debate?” BBS 23(5):645–726 [October 2000]

The rationality debate as a progressive research program

Keith E. Stanovich a1 and Richard F. West a2
a1 Department of Human Development and Applied Psychology, University of Toronto, Toronto, Ontario, M5S 1V6, Canada [email protected]
a2 School of Psychology, James Madison University, Harrisonburg, VA 22807 [email protected]


We did not, as Brakel & Shevrin imply, intend to classify either System 1 or System 2 as rational or irrational. Instrumental rationality is assessed at the organismic level, not at the subpersonal level. Thus, neither System 1 nor System 2 are themselves inherently rational or irrational. Also, that genetic fitness and instrumental rationality are not to be equated was a major theme in our target article. We disagree with Bringsjord & Yang's point that the tasks used in the heuristics and biases literature are easy. Bringsjord & Yang too readily conflate the ability to utilize a principle of rational choice with the disposition to do so. Thus, they undervalue tasks in the cognitive science literature that compellingly reveal difficulties with the latter. We agree with Newton & Roberts that models at the algorithmic level of analysis are crucial, but we disagree with their implication that attention to issues of rationality at the intentional level of analysis impedes work at the algorithmic level of analysis.