An evaluation of dual-process theories of reasoning

Current theories propose that reasoning comprises two underlying systems (Evans & Over, 1996; Sloman, 1996; Stanovich & West, 2000). The systems are identified as having functionally distinct roles, differ according to the type of information encoded, vary according to the level of expressible knowledge, and result in different responses. This article evaluates the arguments and the evidence from a select number of key tasks that have been supportive of dual-reasoning theorists' proposals. The review contrasts the dualist approach with a single-system framework that conjectures that different types of reasoning arise through the graded properties of the representations that are utilized while reasoning, and the different functional roles that consciousness has in cognition. The article concludes by arguing in favor of the alternative framework, which attempts to unify thedifferent forms of reasoning identified by dual-process theorists under a single system.     

Dual-process theories of reasoning: The test of development

Dual-process theories have become increasingly influential in the psychology of reasoning. Though the distinction they introduced between intuitive and reflective thinking should have strong developmental implications, the developmental approach has rarely been used to refine or test these theories. In this article, I review several contemporary dual-process accounts of conditional reasoning that theorize the distinction between the two systems of reasoning as a contrast between heuristic and analytic processes, probabilistic and mental model reasoning, or emphasize the role of metacognitive processes in reflective reasoning. These theories are evaluated in the light of the main developmental findings. It is argued that a proper account of developmental phenomena requires the integration of the main strengths of these three approaches. I propose such an integrative theory of conditional understanding and argue that the modern dual-process framework could benefit from earlier contributions that made the same distinction between intuition and reflective thinking, such as Piaget’s theory.     

Deciding between theories of how reasoning develops is hard

Although Sloutsky agrees with our interpretation of our data, he argues that the totality of the evidence supports his claim that children make inductive generalisations on the basis of similarity. Here we take issue with his characterisation of the alternative hypotheses in his informal analysis of the data, and suggest that a thorough Bayesian analysis, although practically very difficult, is likely to result in a more finely balanced outcome than he suggests.     

Conditional reasoning and the Wason selection task: Biconditional interpretation instead of reasoning bias

Two experiments were conducted to show that the IF … THEN … rules used in the different versions of Wason's (1966 Wason, P. C. 1966. “Reasoning”. In New horizons in psychology I, Edited by: Foss, B. M. Harmondsworth, , UK: Penguin.  [Google Scholar]) selection task are not psychologically—though they are logically—equivalent. Some of these rules are considered by the participants as strict logical conditionals, whereas others are interpreted as expressing a biconditional relationship. A deductive task was used jointly with the selection task to show that the original abstract rule is quite ambiguous in this respect, contrary to deontic rules: the typical “error” made by most people may indeed be explained by the fact that they consider the abstract rule as a biconditional. Thus, there is no proper error or bias in the selection task as it is still argued, but a differential interpretation of the rule. The need for taking into account a pragmatic component in the process of reasoning is illustrated by the experiments.     

Falsifying mental models: Testing the predictions of theories of syllogistic reasoning

Four experiments are reported that tested the claim, drawn from mental models theory, that reasoners attempt to construct alternative representations of problems that might falsify preliminary conclusions they have drawn. In Experiment 1, participants were asked to indicate which alternative conclusion(s) they had considered in a syllogistic reasoning task. In Experiments 2-4, participants were asked to draw diagrams consistent with the premises, on the assumption that these diagrams would provide insights into the mental representation being used. In none of the experiments was there any evidence that people constructed more models for multiple-model than for single-model syllogisms, nor was there any correlation between number of models constructed and overall accuracy. The results are interpreted as showing that falsification of the kind proposed by mental models theory may not routinely occur in reasoning.     

Belief-desire reasoning as a process of selection

Human learning may depend upon domain specialized mechanisms. A plausible example is rapid, early learning about the thoughts and feelings of other people. A major achievement in this domain, at about age four in the typically developing child, is the ability to solve problems in which the child attributes false beliefs to other people and predicts their actions. The main focus of theorizing has been why 3-year-olds fail, and only recently have there been any models of how success is achieved in false-belief tasks. Leslie and Polizzi (Inhibitory processing in the false-belief task: Two conjectures. Developmental Science, 1, 247-254, 1998) proposed two competing models of success, which are the focus of the current paper. The models assume that belief-desire reasoning is a process which selects a content for an agent's belief and an action for the agent's desire. In false belief tasks, the theory of mind mechanism (ToMM) provides plausible candidate belief contents, among which will be a 'true-belief.' A second process reviews these candidates and by default will select the true-belief content for attribution. To succeed in a false-belief task, the default content must be inhibited so that attention shifts to another candidate belief. In traditional false-belief tasks, the protagonist's desire is to approach an object. Here we make use of tasks in which the protagonist has a desire to avoid an object, about which she has a false-belief. Children find such tasks much more difficult than traditional tasks. Our models explain the additional difficulty by assuming that predicting action from an avoidance desire also requires an inhibition. The two processing models differ in the way that belief and desire inhibitory processes combine to achieve successful action prediction. In six experiments we obtain evidence favoring one model, in which parallel inhibitory processes cancel out, over the other model, in which serial inhibitions force attention to a previously inhibited location. These results are discussed in terms of a set of simple proposals for the modus operandi of a domain specific learning mechanism. The learning mechanism is in part modular--the ToMM--and in part penetrable--the Selection Processor (SP). We show how ToMM-SP can account both for competence and for successful and unsuccessful performance on a wide range of belief-desire tasks across the preschool period. Together, ToMM and SP attend to and learn about mental states.     

Dual-process theories of reasoning: Contemporary issues and developmental applications

In this paper, I discuss the current state of theorising about dual processes in adult performance on reasoning and decision making tasks, in which Type 1 intuitive processing is distinguished from Type 2 reflective thinking. I show that there are many types of theory some of which distinguish modes rather than types of thinking and that assumptions about underlying cognitive architecture vary. I show that some dual-system theories have been replaced recently by the idea that we have two or more distinct ‘minds’ with different evolutionary histories. I also present the most recent formulation of my own account of dual processing within hypothetical thinking theory, at a level more easily applied to performance on specific tasks. I then consider implications for cognitive development, pointing out that while Type 2 thinking is clearly linked to the development of cognitive ability, it combines and competes with multiple Type 1 processing systems which persist in adult cognition, each of which could have their own developmental time course. Hence, while dual-process theories can and should inspire much research and theory in cognitive development, the derivation of predictions for cognitive development is far from straightforward.     

The justification and selection of scientific theories

This paper is a critique of a project, outlined by Laudan et al. (1986) recently in this journal, for empirically testing philosophical models of change in science by comparing them against the historical record of actual scientific practice. While the basic idea of testing such models of change in the arena of science is itself an appealing one, serious questions can be raised about the suitability of seeking confirmation or disconfirmation for large numbers of specific theses drawn from a massive list of claims abstracted from the writings of a few philosophers of science. The present paper discusses what one might reasonably expect from a model of change in science and then compares some clusters of theses from Laudan et al. with developments in recent theoretical physics. The results suggest that such straightforward testing of theses may be largely inconclusive.The research reported in this paper was partially supported by NSF grants SES-8318884 and SES-8606472. A preliminary version of this paper was read at the Conference on Testing Theories of Scientific Change held at Virginia Polytechnic Institute and State University, Blacksburg, VA, October 20–22, 1986.     

The implications of processing event sequences for theories of analogical reasoning

Sternberg (1977a, 1977b) has proposed a componential theory of information processing on analogies. The current study attempts convergent validation of the basic findings in verbal analogies by a method that is based on different underlying assumptions. Although the data were generally consistent with Sternberg’s theory, the data indicated thatapplication is better described by two separate events. Furthermore, the extent of individual differences in strategy models was so substantial that a higher level processing operation, such as control strategies, should be postulated, rather than to support a single-strategy model as characterizing Analogy solving.     

The dual-process turn: How recent defenses of dual-process theories of reasoning fail

In response to the claim that the properties typically used to distinguish System 1 from System 2 crosscut one another, Carruthers, Evans, and Stanovich have abandoned the System 1/System 2 distinction. Evans and Stanovich both opt for a dual-process theory, according to which Type-1 processes are autonomous and Type-2 processes use working memory and involve cognitive decoupling. Carruthers maintains a two-system account, according to which there is an intuitive system and a reflective system. I argue that these defenses of dual-process theory face two problems. First, as pointed out by Sloman, these new dual-process theories cast the net of “reasoning” too wide. Second, and more importantly, this singular distinction cannot accomplish the explanatory work needed to support dual-process theory. These theorists must fall back on using various properties from the Standard Menu in explanations, thereby committing these accounts to a “Standard View” that they had hoped to avoid. Thus, these theorists face a dilemma: either the distinction between intuitive and reflective (or autonomous and working memory involving) falls back on using the properties of the Standard Menu, or it lacks the explanatory promise that made dual-process theory attractive.     

Falsification cueing in collective reasoning: example of the Wason selection task

This paper focuses on the effectiveness of groups, as opposed to individuals, in benefiting from falsification cueing in solving the Wason selection task. Consistent with the idea that groups use information that often individuals fail to use, Experiment 1 showed that groups (but not individuals) that received falsification cueing focused more on cue‐consistent evidence in their reasoning. Experiments 2 and 3 showed that the increment in focus on cue‐consistent evidence is moderated by the distribution of the falsification cue within a group. Finally, Experiment 3 demonstrated that the cue distribution affects collective focus on cue‐consistent evidence through the content of the group discussion, namely through mentioning the cue during the discussion. Copyright © 2008 John Wiley & Sons, Ltd.     

Explaining inappropriate strategy selection in a simple reasoning task

People's strategy selections appear to reflect attempts to maximize performance by selecting the most effective option for a particular task or format. Theories that account for such behaviour will be named rational models of strategy selection. However, it is possible to find instances where people are apparently biased towards using less effective strategies, and such behaviour appears to go against these models. Two experiments are reported in which participants were instructed to use first one, and then the other of two possible strategies for solving a compass point directions task (the instructed phase), and were subsequently permitted to use any strategy (the free‐choice phase). A substantial minority of participants selected the less effective spatial strategy during the free‐choice phase. Overall, it was found that people who rely on the spatial strategy when given a free‐choice tend to be those who: (1) have not been given particular incentive to perform as well as possible; (2) have difficulty executing the better alternative, cancellation and (3) are particularly prone to making errors at the spatial strategy. Hence, although evidence was found in support of rational models of strategy selection, it is also suggested that these must additionally take account of the motivational and conceptual difficulties that people may have with a task.     

The natural emergence of reasoning about the afterlife as a developmental regularity

Participants were interviewed about the biological and psychological functioning of a dead agent. In Experiment 1, even 4- to 6-year-olds stated that biological processes ceased at death, although this trend was more apparent among 6- to 8-year-olds. In Experiment 2, 4- to 12-year-olds were asked about psychological functioning. The youngest children were equally likely to state that both cognitive and psychobiological states continued at death, whereas the oldest children were more likely to state that cognitive states continued. In Experiment 3, children and adults were asked about an array of psychological states. With the exception of preschoolers, who did not differentiate most of the psychological states, older children and adults were likely to attribute epistemic, emotional, and desire states to dead agents. These findings suggest that developmental mechanisms underlie intuitive accounts of dead agents' minds.