Much research in the last two decades has demonstrated that human responses deviate from the performance deemed normative according to various models of decision making and rational judgment (e.g., the basic axioms of utility theory). This gap between the normative and the descriptive can be interpreted as indicating systematic irrationalities in human cognition. However, four alternative interpretations preserve the assumption that human behavior and cognition is largely rational. These posit that the gap is due to (1) performance errors, (2) computational (...) limitations, (3) the wrong norm being applied by the experimenter, and (4) a different construal of the task by the subject. In the debates about the viability of these alternative explanations, attention has been focused too narrowly on the modal response. In a series of experiments involving most of the classic tasks in the heuristics and biases literature, we have examined the implications of individual differences in performance for each of the four explanations of the normative/descriptive gap. Performance errors are a minor factor in the gap; computational limitations underlie non-normative responding on several tasks, particularly those that involve some type of cognitive decontextualization. Unexpected patterns of covariance can suggest when the wrong norm is being applied to a task or when an alternative construal of the task should be considered appropriate. Key Words: biases; descriptive models; heuristics; individual differences; normative models; rationality; reasoning. (shrink)

The Cognitive Reflection Test (CRT; Frederick, 2005) is designed to measure the tendency to override a prepotent response alternative that is incorrect and to engage in further reflection that leads to the correct response. It is a prime measure of the miserly information processing posited by most dual process theories. The original three-item test may be becoming known to potential participants, however. We examined a four-item version that could serve as a substitute for the original. Our data show that it (...) displays a.58 correlation with the original version and that it has very similar relationships with cognitive ability, various thinking dispositions, and with several other rational thinking tasks. Combining the two versions into a seven-item test resulted in a measure of miserly processing with substantial reliability (.72). The seven-item version was a strong independent predictor of performance on rational thinking tasks after the variance accounted for by cognitive ability and thinking dispositions had been partialled out. (shrink)

Natural myside bias is the tendency to evaluate propositions from within one's own perspective when given no instructions or cues (such as within-participants conditions) to avoid doing so. We defined the participant's perspective as their previously existing status on four variables: their sex, whether they smoked, their alcohol consumption, and the strength of their religious beliefs. Participants then evaluated a contentious but ultimately factual proposition relevant to each of these demographic factors. Myside bias is defined between-participants as the mean difference (...) in the evaluation of the proposition between groups with differing prior status on the variable. Whether an individual difference variable (such as cognitive ability) is related to the magnitude of the myside bias is indicated by whether the individual difference variable interacts with the between-participants status variable. In two experiments involving a total of over 1400 university students ( n = 1484) and eight different comparisons, we found very little evidence that participants of higher cognitive ability displayed less natural myside bias. The degree of myside bias was also relatively independent of individual differences in thinking dispositions. We speculate that ideas from memetic theory and dual-process theory might help to explain why natural myside bias is quite dissociated from individual difference variables. (shrink)

In this response, we clarify several misunderstandings of the understanding/acceptance principle and defend our specific operationalization of that principle. We reiterate the importance of addressing the problem of rational task construal and we elaborate the notion of computational limitations contained in our target article. Our concept of thinking dispositions as variable intentional-level styles of epistemic and behavioral regulation is explained, as is its relation to the rationality debate. Many of the suggestions of the commentators for elaborating two-process models are easily (...) integrated into our generic dual-process account. We further explicate how we view the relation between System 1 and System 2 and evolutionary and normative rationality. We clarify our attempt to fuse the contributions of the cognitive ecologists with the insights of the original heuristics and biases researchers. (shrink)

Individual differences in performance on a variety of selection tasks were examined in three studies employing over 800 participants. Nondeontic tasks were solved disproportionately by individuals of higher cognitive ability. In contrast, responses on two deontic tasks that have shown robust performance facilitationthe Drinking-age Problem and the Sears Problem-were unrelated to cognitive ability. Performance on deontic and nondeontic tasks was consistently associated. Individuals in the correct/correct cell of the bivariate performance matrix were over-represented. That is, individuals giving the modal response (...) on a nondeontic task (P and Q) were significantly less likely to give the modal response on a deontic task (P and not-Q) than were individuals who made the non-modal P and not-Q selection on nondeontic problems. The implications of the results are discussed within the heuristic-analytic framework of Evans (1996; Evans & Over, 1996) and the optimal data selection model of Oaksford and Chater (1994). (shrink)

Two critical thinking skills—the tendency to avoid myside bias and to avoid one-sided thinking—were examined in three different experiments involving over 1200 participants and across two different paradigms. Robust indications of myside bias were observed in all three experiments. Participants gave higher evaluations to arguments that supported their opinions than those that refuted their prior positions. Likewise, substantial one-side bias was observed—participants were more likely to prefer a one-sided to a balanced argument. There was substantial variation in both types of (...) bias, but we failed to find that participants of higher cognitive ability displayed less myside bias or less one-side bias. Although cognitive ability failed to associate with the magnitude of the myside bias, the strength and content of the prior opinion did predict the degree of myside bias shown. Our results indicate that cognitive ability—as defined by traditional psychometric indicators—turns out to be surprisingly independent of two of the most important critical thinking tendencies discussed in the literature. (shrink)

Individual differences on a variety of framing and conjunction problems were examined in light of Slovic and Tversky's (1974) understanding/acceptance principle-that more reflective and skilled reasoners are more likely to affirm the axioms that define normative reasoning and to endorse the task construals of informed experts. The predictions derived from the principle were confirmed for the much discussed framing effect in the Disease Problem and for the conjunction fallacy on the Linda Problem. Subjects of higher cognitive ability were disproportionately likely (...) to avoid each fallacy. Other framing problems produced much more modest levels of empirical support. It is conjectured that the varying patterns of individual differences are best explained by two-process theories of reasoning (e.g. Evans, 1984, 1996; Sloman, 1996) conjoined with the assumption that the two processes differentially reflect interactional and analytic intelligence. (shrink)

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. (shrink)