Beyond Generic Dual Processes: How Should We Evaluate Scientific Progress? A review of

In Two Minds: Dual Processes and Beyond by Jonathan St. B. T. Evans and Keith Frankish (Eds.) Oxford, England: Oxford University Press, 2009. 369 pp. ISBN 978-0-19-923016-7. $59.95

Reviewed by Edward T. Cokely

Some scholars and scientists are thinking differently about thinking. Roughly, the idea is that humans have, in effect, two separate minds. One mind is said to be evolutionarily older and rapidly gives rise to intuitions (and emotion). The other mind is evolutionarily newer and can yield deliberative and rational thought. The two-minds hypothesis (i.e., generic dual process theory) attempts to explain behavior as the result of the interplay between these two types of independent cognitive processes (often called dual systems). Today, the influence of generic dual process theory is widespread, connecting research in most subfields of psychology as well as neuroscience, economics, philosophy, and other areas (Evans, 2007; Kahneman, 2003; Kahneman & Frederick, 2007; Sloman, 1996; Stanovich & West, 2000). Ironically, however, researchers are of two minds about generic dual processes, documenting fundamental concerns that question both the merit and

sustainability of such a framework (Gigerenzer & Regier, 1996; Keren & Schul, in press; Kruglanski, Erbs, Pierro, Mannetti, & Chun, 2006; Kruglanski & Thompson, 1999; Newell, 1973; Osman, 2004). Can a generic dual process theory provide a fundamental, unifying theory of human cognition?

A Brief Overview The edited book In Two Minds: Dual Processes and Beyond brings together scholars from a variety of disciplines to discuss both specific and generic dual process theories. The book details the many ways in which the history of science and of Western thought has characterized the mind as partitioned, providing greatly needed historical and philosophical perspectives. The book goes on to emphasize modern dual and multiprocess research programs that have emerged over the last 30 years. Broadly, In Two Minds has three aims. First, it attempts to clarify theoretical positions, reviewing technical terms and attempting to refine notions of a generic dual systems theory (Evans, 2007, 2008). Second, it endeavors to increase the exchange among scholars, many of whom have independently developed specific dual or multiprocess theories (Chaiken & Trope, 1999). Finally, it aims to encourage the use and development of dual process theories and their applications. In some regards In Two Minds achieves its goals. It brings together scholars with wide-ranging perspectives and approaches. For example, one chapter presents progress toward a well-specified, multiprocess computational model of cognition (i.e., CLARION; Sun, Merrill, & Peterson, 2001). Another chapter presents an important reconceptualization of the causes of individual differences in intelligence (Stanovich, 2009). Still other chapters deal with topics ranging from philosophy to morality to neuroscience. Most entries do an excellent job of introducing unique perspectives on specific dual or multiprocess theories. This is a major strength and perhaps is the book’s main contribution. In other regards, In Two Minds faces serious challenges. Critically, the book struggles with, and largely fails to acknowledge, its major theoretical limitations—for example, concerns regarding the underspecified and internally inconsistent state of the generic dual process theory (see next section). The proposed generic theory also shows signs of strain from an ever-increasing amount of new and sometimes poorly defined theoretical jargon. To illustrate, the book discusses a new, third generic processing type that serves a key regulatory function. While the Type 3 notion (Stanovich, 2009) addresses the crucial and often neglected influence of metacognition on cognitive performance (Baron, 1978; Cokely & Kelley, 2009; Cokely, Kelley, & Gilchrist, 2006; Stanovich & West, 1998, 2000; Sternberg, 1998), it is not clear that this or other jargon goes beyond what is already widely used (cf. metacognition and cognitive abilities, Hertzog & Robinson, 2005; automatic vs.

controlled processes, Shiffrin & Schneider, 1977). Indeed, historians of science note that the piling of jargon upon jargon is a counterproductive practice that slows progress and can mask deeper problems (Baars, 1986). Taken together, its jargon and somewhat selective review represent the book’s major shortcomings. The intended audience for In Two Minds includes students and professionals who have an interest in human psychology and behavior. Although it is interdisciplinary, it is likely to be best suited for those with some training in and familiarity with cognitive psychology.

Limitations of the Overarching Framework Across several chapters, authors provide an outline of an updated generic dual process theory—a theory that purports to offer a fundamental and unifying approach to human cognition. Roughly, Type 1 processes (“System 1”; p. v) are said to involve evolutionarily older, high-capacity, fast, associative, parallel, unconscious, automatic processes that give rise to intuitions. Alternatively, Type 2 processes (“System 2”; p. v, and sometimes including Type 3 processes) are said to be evolutionarily newer, slower, effortful, serial, conscious, rule-based mechanisms that are demanding of working memory and enable hypothetical and rational thought (e.g., logic). It is important to note that the different components of each processing type are argued to be correlated (e.g., automatic processes tend to be fast and associative in nature), although these factors can also be totally uncorrelated (e.g., rule-based processes need not be effortful). Furthermore, the generic dual process theory is characterized by one of two potential architectures. One, sometimes referred to as parallel–competitive (De Neys, 2006; Evans, 2007), holds that the two processing types operate in parallel, each computing potentially independent information that competes for output (as in a horse race). Alternatively, a default–interventionist characterization holds that System 1 generates intuitions while the other types monitor and correct these intuitions (but see Evans, Chapter 2, for a more thorough treatment of the specifics of the interplay for the two-minds hypothesis). On the surface, there are many appealing aspects of the generic dual process theory. For example, it truly has remarkable explanatory power such that, post hoc, it can explain nearly any pattern of behavior. But this is actually a major limitation, not a virtue. Because the generic theory still only vaguely specifies theoretical parameters (e.g., when two processes will be correlated and when they will be uncorrelated), it can be adjusted to accommodate wide arrays of data yet makes few, if any, unique predictions. In this regard, it is much like the financial analyst who can convincingly explain the behavior of yesterday’s market but who cannot anticipate or plan for tomorrow’s returns. This state of affairs

presents a serious challenge to the theory’s scientific standing, one that remains unresolved (Gigerenzer & Regier, 1996; Keren & Schul, in press; Kruglanski et al., 2006; Kruglanski & Thompson, 1999; Moshman, 2000; Newstead, 2000; Osman, 2004).

What Makes a Good Theory? Nearly 40 years ago, Alan Newell wrote a now-famous article about the dangerous use of binary distinctions in psychology. Far from providing the rungs of a ladder by which psychology gradually climbs to clarity, this form of conceptual structure leads rather to an ever increasing pile of issues, which we weary of or become diverted from, but never really settle. (Newell, 1973, p. 289)

Recently a panel of researchers came to a similar conclusion regarding the current status of dual systems theory at the biannual conference of the European Association for Decision Making, Subjective Property, Utility, and Decision Making (SPUD-22). While the panelists agreed that such notions have a place when one is starting to conceptualize or communicate complicated issues, they rejected the idea that generic dual process dichotomies could provide meaningful scientific progress. Of note, In Two Minds also documents some related concerns, suggesting that “many dual-process theorists are currently rethinking their views and recognizing that the original framework needs to be substantially revised” (p. 23). Perhaps most important, it suggests that “the talk of Systems 1 and 2 should now be discouraged, as it creates more problems than it solves” (Evans, Chapter 2, p. 50). So how do we make and evaluate scientific progress? Can we make progress by performing repair operations on the current generic theory, adding more and more types of processes and shifting to new jargon while also listing out specific (testable) exceptions and predictions? Alternatively, should we abandon generic theory and redouble our efforts to create dual or multiprocess theories with greater specification, even if they are of a more limited scope? This is not an easy problem. Indeed, many of the issues that burden generic dual process theory also plague psychological science more broadly (Gigerenzer, 1998; Newell, 1973). Ultimately, the “right” answer and way forward depend on our goal(s). To my mind, progress comes (a) when we achieve increasing, although not necessarily complete, specification of theories (Marewski & Olsson, 2009; see also Gigerenzer, Todd, & the ABC Research Group, 1999; Marewski, 2009); (b) when we make arguments that leverage and respect issues in the philosophy of science (e.g., theory should be parsimonious, cumulative, prohibitive, internally consistent, and capable of making predictions, preferably risky or

unique predictions; Popper, 1959, 1963; see also Gigerenzer, 1996, 1998; Kruglanski, 2001); (c) when we stay connected to our history, avoiding unnecessary jargon and the redescription of phenomena (e.g., surrogates for theory; Baars, 1986; Gigerenzer, 1998); and (d) when basic research is successfully translated and competes to solve applied problems (Newell & Card, 1985; Todd & Gigerenzer, 2007). After all, all models are “wrong” (i.e., approximations), and so the merits of a theory hinge on the theory’s relative usefulness and rigor. In some of these regards In Two Minds makes progress, as in its attempts to provide interdisciplinary and historical perspectives. Nonetheless, it is very clear that if we are to make meaningful scientific progress, we must move beyond vague and inconsistent notions of generic dual processes.

References Baars, B. J. (1986). The cognitive revolution in psychology. New York, NY: Guilford Press. Baron, J. (1978). Intelligence and general strategies. In G. Underwood (Ed.), Strategies of information processing (pp. 403–450). New York, NY: Academic Press. Chaiken, S., & Trope, Y. (Eds.). (1999). Dual-process theories in social psychology. New York, NY: Guilford Press. go to PsycINFO record Cokely, E. T., & Kelley, C. M. (2009). Cognitive abilities and superior decision making under risk: A protocol analysis and process model evaluation. Judgment and Decision Making, 4, 20–33. go to PsycINFO record Cokely, E. T., Kelley, C. M., & Gilchrist, A. H. (2006). Sources of individual differences in working memory: Contributions of strategy to capacity. Psychonomic Bulletin & Review, 13, 991–997. go to PsycINFO record De Neys, W. (2006). Dual processing in reasoning: Two systems but one reasoner. Psychological Science, 17, 428–433. go to PsycINFO record view article on PsycNET Evans, J. St. B. T. (2007). Hypothetical thinking: Dual processes in reasoning and judgement. Hove, England: Psychology Press. go to PsycINFO record Evans, J. St. B. T. (2008). Dual-processing accounts of reasoning, judgment, and social cognition. Annual Review of Psychology, 59, 255–278. go to PsycINFO record view article on PsycNET Gigerenzer, G. (1996). On narrow norms and vague heuristics: A rebuttal to Kahneman and Tversky (1996). Psychological Review, 103, 592–596. go to PsycINFO record view article on PsycNET Gigerenzer, G. (1998). Surrogates for theories. Theory & Psychology, 8, 195–204. go to PsycINFO record view article on PsycNET

Gigerenzer, G., & Regier, T. (1996). How do we tell an association from a rule? Comment on Sloman (1996). Psychological Bulletin, 119, 23–26. go to PsycINFO record view article on PsycNET Gigerenzer, G., Todd, P. M., & the ABC Research Group. (1999). Simple heuristics that make us smart. New York, NY: Oxford University Press. go to PsycINFO record Hertzog, C., & Robinson, A. E. (2005). Metacognition and intelligence. In O. Wilhelm & R. W. Engle (Eds.), Understanding and measuring intelligence (pp. 101–123). London, England: Sage. Kahneman, D. (2003). A perspective on judgment and choice: Mapping bounded rationality. American Psychologist, 58, 697–720. go to PsycINFO record view article on PsycNET Kahneman, D., & Frederick, S. (2007). Frames and brains: Elicitation and control of response tendencies. Trends in Cognitive Sciences, 11, 45–46. go to PsycINFO record view article on PsycNET Keren, G., & Schul, Y. (in press). Two is not always better than one: A critical evaluation of two-systems theories. Perspectives on Psychological Science. Kruglanski, A. W. (2001). That “vision thing”: The state of theory in social and personality psychology at the edge of the new millennium. Journal of Personality and Social Psychology, 80, 871–875. go to PsycINFO record view article on PsycNET Kruglanski, A. W., Erbs, H., Pierro, A., Mannetti, L., & Chun, W. Y. (2006). On parametric continuities in the world of binary either ors. Psychological Inquiry, 17, 153–165. go to PsycINFO record view article on PsycNET Kruglanski, A. W., & Thompson, E. P. (1999). Persuasion by a single route: A view from the Unimodel. Psychological Inquiry, 10, 83–109. go to PsycINFO record view article on PsycNET Marewski, J. N. (2009). On the theoretical precision and strategy selection problem of a single-strategy approach: A comment on Glöckner, Betsch, and Schindler. Journal of Behavioral Decision Making, 22, 1–5. Marewski, J. N., & Olsson, H. (2009). Beyond the null ritual: Formal modeling of psychological processes. Zeitschrift für Psychologie / Journal of Psychology, 217(1), 49–60. Moshman, D. (2000). Diversity in reasoning and rationality: Metacognitive and developmental considerations. Behavioral and Brain Sciences, 23, 689–690. Newell, A. (1973). You can’t play 20 questions with nature and win: Protective comments on the papers of this symposium. In W. G. Chase (Ed.), Visual information processing (pp. 283–308). New York, NY: Academic Press. Newell, A., & Card, S. K. (1985). The prospects for psychological science in human–computer interaction. Human-Computer Interaction, 1, 209–242. Newstead, S. E. (2000). Are there two different types of thinking? Behavioral and Brain Sciences, 23, 690–691.

Osman, M. (2004). An evaluation of dual-process theories of reasoning. Psychonomic Bulletin & Review, 11, 988–1010. go to PsycINFO record Popper, K. R. (1959). The logic of scientific discovery. London, England: Hutchinson. Popper, K. R. (1963). Conjectures and refutations: The growth of scientific knowledge. London, England: Routledge. Shiffrin, R. M., & Schneider, W. (1977). Controlled and automatic human information processing: II. Perceptual learning, automatic attending, and a general theory. Psychological Review, 84, 127–190. go to PsycINFO record view article on PsycNET Sloman, S. A. (1996). The empirical case for two systems of reasoning. Psychological Bulletin, 119, 3–22. go to PsycINFO record view article on PsycNET Stanovich, K. E. (2009). What intelligence tests miss: The psychology of rational thought. New Haven, CT: Yale University Press. Stanovich, K. E., & West, R. F. (1998). Individual differences in rational thought. Journal of Experimental Psychology: General, 127, 161–188. go to PsycINFO record view article on PsycNET Stanovich, K. E., & West, R. F. (2000). Individual differences in reasoning: Implications for the rationality debate. Behavioral and Brain Sciences, 23, 645–665. go to PsycINFO record view article on PsycNET Sternberg, R. J. (1998). Metacognition, abilities, and developing expertise: What makes an expert student? Instructional Science, 26, 127–140. go to PsycINFO record view article on PsycNET Sun, R., Merrill, E., & Peterson, T. (2001). From implicit skills to explicit knowledge: A bottom-up model of skill learning. Cognitive Science, 25, 203–224. Todd, P. M., & Gigerenzer, G. (2007). Environments that make us smart: Ecological rationality. Current Directions in Psychological Science, 16, 167–171. go to PsycINFO record view article on PsycNET

I wish to thank Dafina Petrova and Paula Parpart for discussions and helpful comments on earlier drafts of this review. I am also grateful to Arie Kruglanski and Gerd Gigerenzer for their general feedback.

PsycCRITIQUES 1554-0138

December 23, 2009, Vol. 54, Release 51, Article 10 © 2009, American Psychological Association