Jonathan St. B. T. Evans's research while affiliated with University of Plymouth and other places

Publications (145)

Article
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Originally identified by Hume, the validity of is–ought inference is much debated in the meta-ethics literature. Our work shows that inference from is to ought typically proceeds from contextualised, value-laden causal utility conditional, bridging into a deontic conclusion. Such conditional statements tell us what actions are needed to achieve or...
Article
I present a critical discussion of dual-process theories of reasoning and decision making with particular attention to the nature and role of Type 2 processes. The original theory proposed that A: Type 2 processes serve to rationalise and support intuitive choices. For most of its history, however, such accounts have emphasised instead B: Type 2 pr...
Article
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There is much evidence that high-capacity reasoners perform better on a variety of reasoning tasks (Stanovich, 1999), a phenomenon that is normally attributed to differences in either the efficacy or the probability of deliberate (Type II) engagement (Evans, 2007). In contrast, we hypothesized that intuitive (Type I) processes may differentiate hig...
Article
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Faced with moral choice, people either judge according to pre-existing obligations (deontological judgment), or by taking into account the consequences of their actions (utilitarian judgment). We propose that the latter coheres with a more general cognitive mechanism - deontic introduction, the tendency to infer normative ('deontic') conclusions fr...
Article
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In a recent article in this journal, Johnson-Laird and colleagues argue that mental model theory (MMT) can integrate logical and probabilistic reasoning. We argue that Johnson-Laird and colleagues make a radical revision of MMT, but to ill effect.
Article
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In a recent article in this journal, Johnson–Laird and colleagues argue that mental models theory (MMT) can integrate logical and probabilistic reasoning [1]. We argue that Johnson-Laird and colleagues make a radical revision of MMT, but to ill effect. This can best be seen in what they say about truth and validity (Box 1). Formerly ([2], p. 651),...
Conference Paper
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An important aspect of information processing and decision making is reasoning; however, this process may be governed by other factors besides logical validity, such as belief bias. In the present study syllogistic reasoning and belief bias were tested by asking participants to decide whether a conclusion can be logically deducted. Within-trial rep...
Article
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There has been a paradigm shift in the psychology of deductive reasoning. Many researchers no longer think it is appropriate to ask people to assume premises and decide what necessarily follows, with the results evaluated by binary extensional logic. Most every day and scientific inference is made from more or less confidently held beliefs and not...
Article
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Humans have a unique ability to generate novel norms. Faced with the knowledge that there are hungry children in Somalia, we easily and naturally infer that we ought to donate to famine relief charities. Although a contentious and lively issue in metaethics, such inference from ‘is’ to ‘ought’ has not been systematically studied in the psychology o...
Article
Wason (196048. Wason, P. C. (1960). On the failure to eliminate hypotheses in a conceptual task. Quarterly Journal of Experimental Psychology, 12, 129–140.View all references) published a relatively short experimental paper, in which he introduced the 2-4-6 problem as a test of inductive reasoning. This paper became one of the most highly cited to...
Article
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The psychology of reasoning and decision making (RDM) shares the methodology of cognitive psychology in that researchers assume that participants are doing their best to solve the problems according to the instruction. Unlike other cognitive researchers, however, they often view erroneous answers evidence of irrationality rather than limited effici...
Article
Throughout this article the authors presume - without justification - that decision making must be a conscious process unless proved otherwise, and they place an unreasonably strict burden of proof on anyone wishing to claim a role for unconscious processing. In addition, I show that their arguments do not, as implied here, impact upon contemporary...
Article
I argue that views of human rationality are strongly affected by the adoption of a two minds theory in which humans have an old mind which evolved early and shares many features of animal cognition, as well as new mind which evolved later and is distinctively developed in humans. Both minds have a form of instrumental rationality-striving for the a...
Article
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The new paradigm in psychology of reasoning is a family of theories sharing common assumptions and research goals. However, there are still some issues under debate. Although authors within the paradigm broadly agree on Bayesianism as a suitable theoretical framework, approaches vary considerably in adopting Bayesian principles to rationality, crea...
Article
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We tested the hypothesis that choices determined by Type 1 processes are compelling because they are fluent, and for this reason they are less subject to analytic thinking than other answers. A total of 104 participants completed a modified version of Wason's selection task wherein they made decisions about one card at a time using a two-response p...
Article
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Dual-process and dual-system theories in both cognitive and social psychology have been subjected to a number of recently published criticisms. However, they have been attacked as a category, incorrectly assuming there is a generic version that applies to all. We identify and respond to 5 main lines of argument made by such critics. We agree that s...
Article
In this article, we respond to the four comments on our target article. Some of the commentators suggest that we have formulated our proposals in a way that renders our account of dual-process theory untestable and less interesting than the broad theory that has been critiqued in recent literature. Our response is that there is a confusion of level...
Article
In two experiments we tested the hypothesis that the mechanisms that produce belief bias generalise across reasoning tasks. In formal reasoning (i.e., syllogisms) judgements of validity are influenced by actual validity, believability of the conclusions, and an interaction between the two. Although apparently analogous effects of belief and argumen...
Article
Along with others we believe there has been a distinct paradigm shift in the psychology of deductive reasoning. Many authors have moved away from a model of rational reasoning based on extensional bivalent logic in favour of a Bayesian approach in which all premises and conclusion are represented with a degree of uncertainty. This leaves the import...
Article
Multiple cue probability learning (MCPL) involves learning to predict a criterion based on a set of novel cues when feedback is provided in response to each judgment made. But to what extent does MCPL require controlled attention and explicit hypothesis testing? The results of two experiments show that this depends on cue polarity. Learning about c...
Article
Dual-process theories of higher cognition, distinguishing between intuitive (Type 1) and reflective (Type 2) thinking, have become increasingly popular, although also subject to recent criticism. A key question, to which a number of contributions in this special issue relate, is how to define the difference between the two kinds of processing. One...
Article
In common with a number of other authors I believe that there has been a paradigm shift in the psychology of reasoning, specifically the area traditionally labelled as the study of deduction. The deduction paradigm was founded in a philosophical tradition that assumed logicality as the basis for rational thought, and provided binary propositional l...
Article
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When the validity of a deductive conclusion conflicts with its believability people often respond in a belief-biased manner. This study used response times to test the selective processing model, which views belief-bias effects as arising from the interplay between superficial heuristic processes and more rigorous analytic processes. Participants w...
Article
Our target article identified normativism as the view that rationality should be evaluated against unconditional normative standards. We believe this to be entrenched in the psychological study of reasoning and decision making and argued that it is damaging to this empirical area of study, calling instead for a descriptivist psychology of reasoning...
Article
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We propose a critique of normativism, defined as the idea that human thinking reflects a normative system against which it should be measured and judged. We analyze the methodological problems associated with normativism, proposing that it invites the controversial "is-ought" inference, much contested in the philosophical literature. This problem i...
Article
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 assumption...
Article
In this study both adolescents with autism spectrum disorder (ASD) and typically developing controls were presented with conditional reasoning problems using familiar content. In this task both valid and fallacious conditional inferences that would otherwise be drawn can be suppressed if counterexample cases are brought to mind. Such suppression oc...
Article
A general two-stage theory of human inference is proposed. A distinction is drawn between heuristic processes which select items of task information as ‘relevant’, and analytic processes which operate on the selected items to generate inferences or judgements. These two stages are illustrated in a selective review of work on both deductive and stat...
Article
Two experiments are reported in which participants are asked to evaluate computer-presented conditional syllogisms consisting of a major premise (conditional rule), a minor premise and a conclusion. As an example the modus tollens inference with an affirmative conditional has the form if p then q, not-q therefore not-p. In these experiments, partic...
Article
The standard procedure for scoring speeded psychometric tests (guessing corrected number right in fixed time) produces scores which depend both on the speed and accuracy of candidates' responding. These in turn depend both on a candidate's ability to perform the task and the compromise between speed and accuracy which is adopted. This paper uses co...
Article
There is indeed extensive evidence that people perform fairly poorly in reasoning tasks and that they often construct arguments for intuitively cued responses. Mercier & Sperber (M&S) may also be right to claim that reasoning evolved primarily as argumentation. However, if it did, the facility became exapted to the function of supporting uniquely h...
Article
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Multiple-cue probability learning (MCPL) involves learning to predict a criterion when outcome feedback is provided for multiple cues. A great deal of research suggests that working memory capacity (WMC) is involved in a wide range of tasks that draw on higher level cognitive processes. In three experiments, we examined the role of WMC in MCPL by i...
Article
A lay definition of intuition holds that it involves immediate apprehension in the absence of reasoning. From a more technical point of view, I argue also that intuition should be seen as the contrastive of reasoning, corresponding roughly to the distinction between Type 1 (intuitive) and Type 2 (reflective) processes in contemporary dual process t...
Article
This paper addresses the issue of how negative components affect people's ability to draw conditional inferences. The study was motivated by an attempt to resolve a difficulty for the mental models theory of Johnson-Laird and Byrne, whose account of matching bias in the selection task is apparently inconsistent with Johnson-Laird's explanation of t...
Article
We report the results of three experiments designed to assess the role of suppositions in human reasoning. Theories of reasoning based on formal rules propose that the ability to make suppositions is central to deductive reasoning. Our first experiment compared two types of problem that could be solved by a suppositional strategy. Our results showe...
Chapter
This chapter examines how the premise of an introduction inference has itself been derived. It first considers inferring a conditional, 'if not-p then q', as a conclusion from a disjunction, 'p or q'. The chapter then asks: Under what conditions is this inference justified? Will people endorse this inference when it is justified and refuse to endor...
Article
In this paper we examine the way disjunctive choices work in conversational context. We focus on disjunctive deontic rules, such as ‘you must either submit an essay or attend an exam’. According to the Gricean maxim of orderliness, a derivative of the maxim of manner, people should interpret the first-mentioned option as the one preferred by the sp...
Article
The conjunction fallacy has been cited as a classic example of the automatic contextualisation of problems. In two experiments we compared the performance of autistic and typically developing adolescents on a set of conjunction fallacy tasks. Participants with autism were less susceptible to the conjunction fallacy. Experiment 2 also demonstrated t...
Article
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Everyday conditional reasoning is typically influenced by prior knowledge and belief in the form of specific exceptions known as counterexamples. This study explored whether adolescents with autism spectrum disorder (ASD; N = 26) were less influenced by background knowledge than typically developing adolescents (N = 38) when engaged in conditional...
Article
Despite the popularity of the Wason selection task in the psychology of reasoning, doubt remains as to whether card choices actually reflect a process of reasoning. One view is that while participants reason about the cards and their hidden sides-as indicated by protocol analysis-this reasoning merely confabulates explanations for cards that were p...
Article
Marewski, Gaissmaier and Gigerenzer (2009) present a review of research on fast and frugal heuristics, arguing that complex problems are best solved by simple heuristics, rather than the application of knowledge and logical reasoning. We argue that the case for such heuristics is overrated. First, we point out that heuristics can often lead to bias...
Article
We report a large study in which participants are invited to draw inferences from causal conditional sentences with varying degrees of believability. General intelligence was measured, and participants were split into groups of high and low ability. Under strict deductive-reasoning instructions, it was observed that higher ability participants were...
Article
This excellent target article helps to resolve a problem for dual-process theories of higher cognition. Theorists posit two systems, one of which appears to be conscious and volitional. It seems to control some behaviours but to confabulate explanations for others. I argue that this system is only conscious in an illusory sense and that all self-ex...
Article
I agree with Oaksford & Chater (O&C) that human beings resemble Bayesian reasoners much more closely than ones engaging standard logic. However, I have many problems with their “rational analysis” framework, which appears to be rooted in normative rather than ecological rationality. The authors also overstate everyday rationality and neglect to acc...
Article
In this study, we examine the role of beliefs in conditional inference in two experiments, demonstrating a robust tendency for people to make fewer inferences from statements they disbelieve, regardless of logical validity. The main purpose of this study was to test whether participants are able to inhibit this belief effect where it constitutes a...
Article
Dual-process theories of cognition are to be found everywhere in psychology although the literatures concerned may contain little or no cross referencing to each other. These theories come under many labels, but at least superficially all seem to be making a similar distinction (see Evans 2008; and Frankish and Evans, this volume). One question add...
Article
[About the book] This book explores the idea that we have two minds - automatic, unconscious, and fast, the other controlled, conscious, and slow. In recent years there has been great interest in so-called dual-process theories of reasoning and rationality. According to such theories, there are two distinct systems underlying human reasoning - an e...
Article
Previous studies have suggested that a minority of university students, of lower cognitive ability, are inclined to interpret abstract conditional statements, if p then q, as if they were conjunctions: p and q. In the present study we administered the conditional truth table task to a large sample of students (n = 160), but using realistic, everyda...
Article
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Three experiments investigated the effect of rarity on people's selection and interpretation of data in a variant of the pseudodiagnosticity task. For familiar (Experiment 1) but not for arbitrary (Experiment 3) materials, participants were more likely to select evidence so as to complete a likelihood ratio when the initial evidence they received w...
Article
In this study, we focus on the conditions which permit people to assert a conditional statement of the form 'if p then q' with conversational relevance. In a broadly decision-theoretic approach, also drawing on hypothetical thinking theory [Evans, J. St. B. T. (2007). Hypothetical thinking: Dual processes in reasoning and judgement. Hove, UK: Psych...
Article
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Faced with extreme demands, hypothetical thinking runs the danger of total failure. Paradoxical propositions such as the Liar ("I am lying") provide an opportunity to test it to its limits, while the Liar's nonparadoxical counterpart, the Truthteller ("I am telling the truth"), provides a useful comparison. Two experiments are reported, one with ab...
Article
This article reviews a diverse set of proposals for dual processing in higher cognition within largely disconnected literatures in cognitive and social psychology. All these theories have in common the distinction between cognitive processes that are fast, automatic, and unconscious and those that are slow, deliberative, and conscious. A number of...
Article
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The ability to entertain possibilities and draw inferences about them is essential to human intelligence. We examine the hypothesis that conditional if-then statements trigger a mental simulation process in which people suppose the antecedent (if statement) to be true and evaluate the consequent (then statement) in that context. On the assumption t...
Article
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Recent studies have shown the existence of two qualitatively distinct groups of people based on how they judge the probability of a conditional statement. The present study was designed to test whether these differences are rooted in distinctive means of processing conditional statements and whether they are linked to differences in general intelli...
Article
In this paper, I show that the question of how dual process theories of reasoning and judgement account for conflict between System 1 (heuristic) and System 2 (analytic) processes needs to be explicated and addressed in future research work. I demonstrate that a simple additive probability model that describes such conflict can be mapped on to thre...
Article
Hypothetical thought involves the imagination of possibilities and the exploration of their consequences by a process of mental simulation. Using a recently developed theoretical framework called Hypothetical Thinking Theory, Jonathan St. B. T. Evans provides an integrated theoretical account of a wide range of psychological studies on hypothesis t...
Article
We agree that current evolutionary accounts of base-rate neglect are unparsimonious, but we dispute the authors' account of the effect in terms of parallel associative and rule-based processes. We also question their assumption that cueing of nested set relations facilitates performance due to recruitment of explicit reasoning processes. In our acc...
Article
According to the suppositional theory of conditionals, people assess their belief in a conditional statement of the form "if p then q" by conducting a mental simulation on the supposition of p in which they assess their degree of belief in q. This leads to them to the judge the probability of a conditional statement to be equal to the conditional p...
Article
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Conditionals in natural language are central to reasoning and decision making. A theoretical proposal called the Ramsey test implies the conditional probability hypothesis: that the subjective probability of a natural language conditional, P(if p then q), is the conditional subjective probability, P(q/p). We report three experiments on causal indic...
Article
An extensively revised heuristic-analytic theory of reasoning is presented incorporating three principles of hypothetical thinking. The theory assumes that reasoning and judgment are facilitated by the formation of epistemic mental models that are generated one at a time (singularity principle) by preconscious heuristic processes that contextualize...
Article
Under the suppositional account of conditionals, when people think about a conditional assertion, "if p then q," they engage in a mental simulation in which they imagine p holds and evaluate the probability that q holds under this supposition. One implication of this account is that belief in a conditional equates to conditional probability [P(q/p)...
Article
The aim of the present research was to develop a difficulty model for logical reasoning problems involving complex ordered arrays used in the Graduate Record Examination. The approach used involved breaking down the problems into their basic cognitive elements such as the complexity of the rules used, the number of mental models required to represe...
Article
P. N. Johnson-Laird and R. M. J. Byrne proposed an influential theory of conditionals in which mental models represent logical possibilities and inferences are drawn from the extensions of possibilities that are used to represent conditionals. In this article, the authors argue that the extensional semantics underlying this theory is equivalent to...
Article
In this study, we examine the belief bias effect in syllogistic reasoning under both standard presentation and in a condition where participants are required to respond within 10 seconds. As predicted, the requirement for rapid responding increased the amount of belief bias observed on the task and reduced the number of logically correct decisions,...
Article
Informal reasoning typically draws on a wider range of inferential behaviour than is measured by traditional inference tasks. In this paper, we developed several tasks to study informal reasoning with two novel types of conditional statements: Persuasions (e.g., if the Kyoto accord is ratified, greenhouse gas emissions will be reduced) and dissuasi...
Article
In this paper, I discuss conditionals as illocutionary speech acts whose interpretation depends upon the whole of the social context in which they are uttered and whose purpose is to affect the opinions and actions of others. I argue for a suppositional approach to conditional statements based in what philosophers call the Ramsey test and developin...
Article
We report two experiments in which participants are trained using a multicue probability learning (MCPL) task, which attempts to simulate the acquisition of expert judgement by experience in the real world. Participants were asked to predict performance in certain occupations given a profile of personality test results with trial-by-trial outcome f...