The recent intense interest in conspiratorial thinking is fuelled by the perception that belief in conspiracies is highly irrational. However, there have been few studies that have examined the associations of conspiracy belief with a comprehensive battery of rational thinking tasks that tap both epistemic and instrumental rationality. The Comprehensive Assessment of Rational Thinking (CART) provides an opportunity to do just that because one of the subtests on the CART assesses the tendency to believe false conspiracies. That subtest is in (...) the part of the CART that measures the presence of contaminated mindware—stored declarative knowledge that embodies poorly justified beliefs. Converging analyses (N = 747) using the 18 subtests and four thinking dispositions measured on the CART indicated that three variables were key predictors of conspiratorial thinking: superstitious thinking, actively open-minded thinking, and probabilistic reasoning. Theoretical consideration of these best predictors, and of the variables that predict the endorsement of true conspiracies, led us to rethink the classification of conspiracy belief as contaminated mindware and move instead towards a conception of conspiratorial thinking as a cognitive style. (shrink)

Propositional attitude generics such as “Experts think early humans ate grass” report an epistemic state (e.g., think, believe, say) that is generalised to a wider community (e.g., Experts, Scientists, Academics). These generics are often used in place of quantified claims (e.g., “Some experts think…”) but three pre-registered experiments (N = 4891) indicate that this lexical choice risks misrepresenting the true degree of scientific consensus. Relative to “Some experts think…” the generic “Experts think…” was more likely to be understood as “All (...) Experts” or “Possibly all Experts” and less likely to invite the scalar inference “Not all Experts.” Consistent with this, the choice to use generic language became increasingly likely as expert consensus approached unanimity. Propositional attitude generics can imply a high degree of consensus and keep open the possibility of universal agreement. To avoid overgeneralisation, they should be used with caution where the objective degree of consensus is unknown. (shrink)

Based on the distinction between global and local levels of visual perception, here we studied different levels of reasoning in visual analogies. Specifically, we created problems that could be solved by inferring relations either between the global shapes (global path) or the underlying objects (object path). The problems varied in the saliency of the global shape, in the colour and familiarity of the objects, and in the presentation of the visual problem (simultaneous or sequential). The results of three studies showed (...) that the global path was used more frequently than the object path, particularly for images with salient global shapes such as objects placed in a circle. However, neither colour nor object familiarity affected the tendency to use the object path. Importantly, the tendency to use the global path correlated with analogical problem-solving in other visual and verbal tasks. Overall, these findings suggest that the global precedence observed in image perception also applies to visual analogical reasoning. Furthermore, the tendency to use the global path can be regarded as an informative measure of individual differences. (shrink)

How people distinguish well-justified from poorly justified arguments is not well known. To study the involvement of intuitive and analytic cognitive processes, we contrasted participants’ personal beliefs with argument strength that was determined in relation to established criteria of sound argumentation. In line with previous findings indicating that people have a myside bias, participants (N = 249) made more errors on conflict than on no-conflict trials. On conflict trials, errors and correct responses were practically equal in terms of response times (...) and mouse-tracking indices of hesitation. Similarly to recent findings on formal reasoning, these findings indicate that correct reasoning about informal arguments may not necessitate corrective analytic processing. We compared findings across four argument schemes but found few differences. The findings are discussed in light of intuitive logic theories and the notion that evaluating informal arguments could be based on implicit knowledge of argument criteria. (shrink)

The conjunction fallacy is the well-documented reasoning error on which people rate a conjunction A∧B as more probable than one of its conjuncts, A. Many explanations appeal to the fact that B has a high probability in the given scenarios, but Katya Tentori and collaborators have challenged such approaches. They report experiments suggesting that degree of confirmation—rather than probability—is the central determinant of the conjunction fallacy. In this paper, we have two goals. First, we address a confound in Tentori et (...) al.’s experiments: they failed to control for the fact that in their stimuli where B is confirmed, it is also conversationally relevant in the sense that it fits with the topic or question under discussion. Conversely, when B has a high probability but is not confirmed, it is conversationally irrelevant. Consequently, it is possible that conversational relevance, rather than confirmation, is responsible for the differences they found between confirmed and probable hypotheses. Second, inspired by recent theoretical work, we aim to give the first empirical investigation of the hypothesis that this type of conversational relevance on its own—independently of degree of confirmation—can be an important factor in the conjunction fallacy. We report on two experiments that vary Tentori et al.’s design by making B relevant without changing its degree of probability or confirmation. We found that doing so increases the rate of the conjunction fallacy, suggesting that relevance plays an important role in the conjunction fallacy. (shrink)