Naive theories and causal deduction

Probabilistic and Deductive Reasoning in the Human Brain

Reasoning is a process of inference from given premises to new conclusions. Deductive reasoning is truth-preserving and conclusions can only be either true or false. Probabilistic reasoning is based on degrees of belief and conclusions can be more or less likely. While deductive reasoning requires people to focus on the logical structure of the inference and ignore its content, probabilistic reasoning requires the retrieval of prior knowledge from memory. Recently, however, some researchers have denied that deductive reasoning is a faculty of the human mind. What looks like deductive inference might actually also be probabilistic inference, only with extreme probabilities. We tested this assumption in an fMRI experiment with two groups of participants: one group was instructed to reason deductively, the other received probabilistic instructions. They could freely choose between a binary and a graded response to each problem. The conditional probability and the logical validity of the inferences were systematically varied. Results show that prior knowledge was only used in the probabilistic reasoning group. These participants gave graded responses more often than those in the deductive reasoning group and their reasoning was accompanied by activations in the hippocampus. Participants in the deductive group mostly gave binary responses and their reasoning was accompanied by activations in the anterior cingulate cortex, inferior frontal cortex, and parietal regions. These findings show that (1) deductive and probabilistic reasoning rely on different neurocognitive processes, (2) people can suppress their prior knowledge to reason deductively, and (3) not all inferences can be reduced to probabilistic reasoning.

Alternatives or syntactic negation? Adults’ and children’s preferences for constructing counterfactual possibilities

Reasoning with counterfactuals such as “if his sister had entered silently, the child would have been awake”, requires considering what is conjectured (“his sister entered silently”) and what is the counterfactual possibility (“his sister did not enter silently”). In two experiments, we test how both adults (Study 1) and children from 8 to 12 years (Study 2) construct counterfactual possibilities about the cause of an effect (“the child was awake because…”). We test specifically whether people construct the counterfactual possibility by recovering alternatives, for example, “the alarm clock sounded” or by using the syntactic negation using propositional symbols (“his sister did not enter silently”). Moreover, as children show difficulty in thinking with abstract contents, we test whether they construct the counterfactual possibility more readily by recovering concrete alternatives (“the alarm clock sounded”) rather than abstract alternatives (“he had trouble sleeping”). Results showed that children, as well as adults, recovered the alternative as the cause of the effect rather than the negation. Moreover, children, unlike adults, created the counterfactual possibility more frequently by recovering concrete situations rather than abstract situations.

Specificity effects in reasoning with counterintuitive and arbitrary conditionals

When people have prior knowledge about an inference, they accept conclusions from specific conditionals (e.g., “If Jack does sports, then Jack loses weight”) more strongly than for unspecific conditionals (e.g., “If a person does sports, then the person loses weight”). But can specific phrasings also elevate the acceptance of conclusions from unbelievable conditionals? In Experiment 1, we varied the specificity of counterintuitive conditionals, which described the opposite of what is expected according to everyday experiences (“If Lena/a person studies hard, then Lena/the person will not do well on the test”). In Experiment 2, we varied the specificity of arbitrary conditionals, which had no obvious link between antecedent and consequent (“If Mary/a person goes shopping, then Mary/ the person gets pimples”). All conditionals were embedded in MP and AC inferences. Participants were instructed to reason as in daily life and to evaluate the conclusions on a 7-point Likert scale. Our results showed a specificity effect in both experiments: participants gave higher acceptance ratings for specific than for unspecific conditionals.

Reasoning strategy vs cognitive capacity as predictors of individual differences in reasoning performance

The dual strategy model posits that reasoners rely on two information processing strategies when making inferences: The statistical strategy generates a rapid probabilistic estimate based on associative access to a wide array of information, and the counterexample strategy uses a more focused representation allowing for a search for potential counterexamples. In this paper, we focused on individual differences in strategy use as a predictor of performance on four reasoning tasks: Belief bias, base rate neglect, conjunction fallacy, and denominator neglect. Predictions from the strategy use model were contrasted with predictions from Dual Process Theories, which suggest that individual differences in performance reflect variations in cognitive ability. In each of four studies, a large number (N ≈ 200) completed one of the above reasoning tasks, a strategy use diagnostic questionnaire, and measures of IQ, cognitive reflection, and numeracy. In three of four studies, individual differences in strategy use predicted differences in reasoning performance when the effects of the other variables were eliminated. Bayesian analysis indicated that none of the individual differences measures predicted a significant portion of variance on the conjunction fallacy task, and that strategy use was a strong predictor on the remaining three tasks. This research suggests that the type of strategy that is adopted paves a road to successful reasoning that is independent of cognitive capacity.

Find extra options or reason badly: An investigation of children's reasoning with incompatibility statements

The false dilemma or dichotomy is a logical fallacy that occurs when interlocuters accept the premises in an incompatibility statement as being jointly exhaustive (i.e., leaving no third option), whereas that is in fact not the case. Brisson et al. [Memory & Cognition (2018), Vol. 46, pp. 657-670] investigated this fallacy in an adult sample and discovered a content effect that influenced participants' performance. The current study aimed to elaborate on these findings by establishing whether similar patterns could be observed with children. A number of age-appropriate incompatibility premises were constructed. For every item, four different inferential problems were presented (Affirm First, Affirm Second, Deny First, and Deny Second) with three potential answers to choose from (X, not X, or uncertainty regarding X). A sample of 192 volunteer children, with ages ranging from 8 to 13 years, was collected. Statistical analysis showed no significant effect for participants' age but did reveal main effects for premise validity and the amount of available "third options" (possibilities outside of the presented dichotomy). These results are a clear replication of the general effects on adults found by Brisson et al. Affirm inferences were also easy for children, Deny inferences were difficult (even more so than for adults), and content had a profound effect on participants' performance. Whenever more third options could be generated, children were less likely to fall into the false dilemma fallacy. Our findings thus further support the idea that reasoning with incompatibilities is influenced by the same semantic retrieval processes that have been previously related to human conditional reasoning.

Much Ado About Nothing: The Mental Representation of Omissive Relations

When the absence of an event causes some outcome, it is an instance of omissive causation. For instance, not eating lunch may cause you to be hungry. Recent psychological proposals concur that the mind represents causal relations, including omissive causal relations, through mental simulation, but they disagree on the form of that simulation. One theory states that people represent omissive causes as force vectors; another states that omissions are representations of contrasting counterfactual simulations; a third argues that people think about omissions by representing sets of iconic possibilities – mental models – in a piecemeal fashion. In this paper, we tease apart the empirical predictions of the three theories and describe experiments that run counter to two of them. Experiments 1 and 2 show that reasoners can infer temporal relations from omissive causes – a pattern that contravenes the force theory. Experiment 3 asked participants to list the possibilities consistent with an omissive cause – it found that they tended to list particular privileged possibilities first, most often, and faster than alternative possibilities. The pattern is consistent with the model theory, but inconsistent with the contrast hypothesis. We marshal the evidence and explain why it helps to solve a long-standing debate about how the mind represents omissions.

Conditional content, explicit information and generating cases: Sources for suppressing inferences

In the present study, we evaluate the suppression effect by asking participants to make inferences with everyday conditionals ("if A, then B"; "if Ana finds a friend, then she will go to the theatre"), choosing between three possible conclusions ("she went to the theatre"; "she did not go to the theatre"; "it cannot be concluded"). We test how these inferences can be influenced by three factors: a) when the content of the conditional induces us to think about disabling conditions that prevent us from accepting the consequent (A and ¬B) or alternative conditions that induce us to think about other antecedents that could also lead to the consequent (¬A and B), b) when explicit information is given about what really happened (e.g. Ana found a friend but they did not go to the theatre; or Ana did not find a friend but she went to the theatre) and c) when participants have to look for concrete disabling (e.g. Ana's friend had to work) and alternative cases (e.g. Ana's sister wanted to go to the theatre) before making the inferences. Previous studies have shown what were called "suppression effects": disabling conditions reduced valid inferences while considering alternatives led to a reduction in fallacies. These two "suppression effects" were shown in Experiment 1: a) in an Implicit condition that included just the content factor of the conditional and b) with a greater magnitude in a second Explicit condition that included the three factors (content, explicit information and search for counterexamples). Experiment 2 compared the same Explicit condition with another in which participants, instead of looking for counterexamples, completed a control task of looking for synonyms. In addition, half the participants looked for a few items (2 cases) and the other half for many items (5 cases). Results again showed the suppressing effect in all the conditions, but the magnitude was greater in the counterexample condition. No relevant differences were obtained according to the number of cases generated; the most relevant result was that the factors provided an additive effect on the suppression.

Reasoning With Conditionals About Everyday and Mathematical Concepts in Primary School

A research link between conditional reasoning and mathematics has been reported only for late adolescents and adults, despite claims about the pivotal importance of conditional reasoning, i.e., reasoning with if–then statements, in mathematics. Secondary students’ problems with deductive reasoning in mathematics have been documented for a long time. However, evidence from developmental psychology shows that even elementary students possess some early conditional reasoning skills in familiar contexts. It is still an open question to what extent conditional reasoning with mathematical concepts differs from conditional reasoning in familiar everyday contexts. Based on Mental Model Theory (MMT) of conditional reasoning, we assume that (mathematical) content knowledge will influence the generation of models, when conditionals concern mathematical concepts. In a cross-sectional study, 102 students in Cyprus from grades 2, 4, and 6 solved four conditional reasoning tasks on each type of content (everyday and mathematical). All four logical forms, modus ponens (MP), modus tollens (MT), denial of the antecedent (DA), and affirmation of the consequent (AC), were included in each task. Consistent with previous findings, even second graders were able to make correct inferences on some logical forms. Controlling for Working Memory (WM), there were significant effects of grade and logical form, with stronger growth on MP and AC than on MT and DA. The main effect of context was not significant, but context interacted significantly with logical form and grade level. The pattern of results was not consistent with the predictions of MMT. Based on analyses of students’ chosen responses, we propose an alternative mechanism explaining the specific pattern of results. The study indicates that deductive reasoning skills arise from a combination of knowledge of domain-general principles and domain-specific knowledge. It extends results concerning the gradual development of primary students’ conditional reasoning with everyday concepts to reasoning with mathematical concepts adding to our understanding of the link between mathematics and conditional reasoning in primary school. The results inspire the development of educational interventions, while further implications and limitations of the study are discussed.

Reasoning strategies and semantic memory effects in deductive reasoning

Growing evidence supports the dual-strategy model, which suggests that reasoners have access to both a statistical and a counterexample reasoning strategy. In this paper, we explore further the processes underlying strategy use. We report three studies, the aim of which was to clarify the relation between this model and two forms of everyday reasoning. One of the most robust effects found with conditional reasoning with meaningful premises is the effect of alternative antecedents on the endorsement of AC and DA inferences. In a first study, we presented participants with conditional reasoning problems having more or fewer accessible alternatives as well as our dual-strategy diagnostic questionnaire. As hypothesized, results showed that strategy use had an independent effect on the inferences made with the AC and DA forms, over and above the effect of the number of antecedents, but was not related to responding to the MP and the MT forms. In a second study, we found that this relation extended to reasoning from an incompatibility statement. Finally, a third study showed that this relationship did not hold with probabilistic rather than logical response instructions, suggesting that the way reasoners transform a probabilistic evaluation into a dichotomous judgment is a key determinant of strategy use.

Divergent Thinking Promotes Deductive Reasoning in Preschoolers

This study explored the hypothesis that preschoolers' deductive reasoning would be improved by encouraging use of divergent thinking (DT). Children of 4-5 years of age (n = 120) were randomly given DT or neutral control exercises before deductive reasoning problems. To allow a stronger test of the hypothesis, half of the children receiving the DT exercises were given explicit examples, which have been shown to reduce ideational originality. Results indicate that, as predicted, DT exercises without examples significantly improved rates of deductive responding, compared to exercises with examples and the control condition. These findings indicate that DT is a key component in the early beginnings of deductive reasoning. Some educational implications are discussed.

Validity and Persuasiveness of Conditional Arguments

Forty college students evaluated 80 conditional arguments with respect to both validity and persuasiveness. The arguments were of four types, two valid (modus ponens and modus tollens) and two invalid (involving affirmation of the consequent and denial of the antecedent). Participants were not good at distinguishing between valid and invalid arguments, although they did so better than at chance. Invalid arguments that were considered to be persuasive were almost 3 times as likely to be judged to be valid as were invalid arguments that were considered not to be persuasive. Whether an argument was judged to be persuasive was influenced by several variables, including the argument’s logical status, its believed logical status, whether the conclusion was believed by the evaluator to be a true statement of fact, whether the minor premise alone could be considered to be an adequate basis for judging the conclusion to be true, whether the argument’s conclusion or any of its premises was (or could be considered to be) false, and how the antecedent and consequent of the major premise were related. Various models of reasoning that predict some of the results are discussed, but there is no extant model that fully explains the relationship between the perceived validity and the perceived persuasiveness of conditional arguments.

The relationship between dietary restraint and deficits in reasoning about causes of obesity

Objective: Increased levels of dietary restraint are associated with deficits on many cognitive tasks. Less is known about how individual differences in restraint influences complex cognition such as reasoning which is the focus of this research.Design: Two experimental studies are reported. In study 1, participants (n = 158) completed a causal conditional reasoning task with statements about weight-related and general causal relationships. Study 2 replicated and extended study 1. Participants (n = 108) completed a causal conditional reasoning task focusing on behavioural causes of weight change or general statements.Main outcome measure: Causal conditional reasoning task performance.Results: In study 1, levels of dietary restraint were negatively associated with reasoning abilities for weight-related statements only. Study 2 replicated the negative association between dietary restraint and reasoning finding the effect in both weight-related, and general, causal judgements.Conclusion: The novel findings show that individual differences in dietary restraint have a wider relationship with cognition than previously demonstrated. Results tentatively support theoretical explanations of a reduction in cognitive capacity, rather than differences in belief, explaining reasoning deficits. These findings open an interesting avenue for research and might have implications for effective decision making about personal health behaviours, such as food choice.

The role of causal models and beliefs in interpreting health claims

OBJECTIVE

Health claims on food packaging are regulated to inform and protect consumers; however, many consumers do not accurately interpret the meaning of the claims. Whilst research has shown different types of misinterpretation, it is not clear how those interpretations are formed. The aim of this study was to elicit the causal beliefs and causal models about food and health held by consumers, that is their understanding of the causal relationships between nutrients, health outcomes, and the causal pathways connecting them, and investigate how well this knowledge explains the variation in inferences they draw about health benefits from health claims.

METHOD

A total of 400 participants from Germany, the Netherlands, Spain, Slovenia, and the United Kingdom were presented with seven authorized health claims and drew inferences about the health benefits of consuming nutrients specified in the claim. Then, their personal causal models of health were elicited along with their belief in the truth and familiarity with the claims.

RESULTS

The strength of inferences about health benefits that participants drew from the claims was predicted independently by the strength of the relevant causal pathways within the causal model, and belief in the truth of the claim, but not familiarity with the claim. Participants drew inferences about overall health benefits of the nutrients by extrapolating from their causal models of health.

CONCLUSION

Consumers' interpretation of claims is associated with their belief in the claim and their causal models of health. This prior knowledge is used to interpret the claim and draw inferences about overall health benefits that go beyond the information in the claim. Therefore, efforts to improve consumers' understanding and interpretation of health claims must address both their wider causal models of health and their knowledge of specific claims. Statement of Contribution What is already known on this subject? Health claims influence the likelihood of buying a product. But consumers do not accurately understand or interpret health claims. What does this study add? Consumers' interpretation of health claims is mediated by their personal causal model of health. Consumers draw inferences that go beyond what is claimed by extrapolating from their personal causal model of health. Consumers are also influenced directly by their belief in the claim, but not frequency of exposure to it.

Reasoning from an incompatibility: False dilemma fallacies and content effects

In the present studies, we investigated inferences from an incompatibility statement. Starting with two propositions that cannot be true at the same time, these inferences consist of deducing the falsity of one from the truth of the other or deducing the truth of one from the falsity of the other. Inferences of this latter form are relevant to human reasoning since they are the formal equivalent of a discourse manipulation called the false dilemma fallacy, often used in politics and advertising in order to force a choice between two selected options. Based on research on content-related variability in conditional reasoning, we predicted that content would have an impact on how reasoners treat incompatibility inferences. Like conditional inferences, they present two invalid forms for which the logical response is one of uncertainty. We predicted that participants would endorse a smaller proportion of the invalid incompatibility inferences when more counterexamples are available. In Study 1, we found the predicted pattern using causal premises translated into incompatibility statements with many and few counterexamples. In Study 2A, we replicated the content effects found in Study 1, but with premises for which the incompatibility statement is a non-causal relation between classes. These results suggest that the tendency to fall into the false dilemma fallacy is modulated by the background knowledge of the reasoner. They also provide additional evidence on the link between semantic information retrieval and deduction.

Beyond Markov: Accounting for independence violations in causal reasoning

Although many theories of causal cognition are based on causal graphical models, a key property of such models-the independence relations stipulated by the Markov condition-is routinely violated by human reasoners. This article presents three new accounts of those independence violations, accounts that share the assumption that people's understanding of the correlational structure of data generated from a causal graph differs from that stipulated by causal graphical model framework. To distinguish these models, experiments assessed how people reason with causal graphs that are larger than those tested in previous studies. A traditional common cause network (Y₁←X→Y₂) was extended so that the effects themselves had effects (Z₁←Y₁←X→Y₂→Z₂). A traditional common effect network (Y₁→X←Y₂) was extended so that the causes themselves had causes (Z₁→Y₁→X←Y₂←Z₂). Subjects' inferences were most consistent with the beta-Q model in which consistent states of the world-those in which variables are either mostly all present or mostly all absent-are viewed as more probable than stipulated by the causal graphical model framework. Substantial variability in subjects' inferences was also observed, with the result that substantial minorities of subjects were best fit by one of the other models (the dual prototype or a leaky gate models). The discrepancy between normative and human causal cognition stipulated by these models is foundational in the sense that they locate the error not in people's causal reasoning but rather in their causal representations. As a result, they are applicable to any cognitive theory grounded in causal graphical models, including theories of analogy, learning, explanation, categorization, decision-making, and counterfactual reasoning. Preliminary evidence that independence violations indeed generalize to other judgment types is presented.

Necessity, Sufficiency, and Perspective Effects in Causal Conditional Reasoning

A growing body of research indicates that in causal conditional reasoning, the conclusion that P is necessary for Q is suppressed where alternative conditions for Q are available. Similarly, the conclusion that P is sufficient for Q is suppressed where disabling conditions for P or additional requirements for Q are available. This paper describes experiments in which these factors were used to produce “perspective effects” in causal contexts that appear identical to the perspective effects found in previous research with deontic tasks. It is therefore proposed that deontic perspective effects are themselves also attributable to the influence of pragmatic factors upon perceived necessity and sufficiency. A generalized theory based on a modification of the mental model theory of deontic reasoning is presented, which accounts for perspective effects across the two domains.

Rephrasing between Disjunctives and Conditionals: Mental Models and the Effects of Thematic Content

Two experiments are reported that investigate whether the logical equivalence of conditionals and disjunctives is paralleled by a psychological equivalence. In these experiments, subjects rephrased from one form into the other. Experiment 1 demonstrated strong effects of familiarity and causality of rule content. Similar findings were found in Experiment 2 with a different conditional rule syntax. An account of the experiments is given in terms of mental models theory: In this account, task performance can be seen to depend upon the extent to which the model sets used by subjects to generate rephrasings are complete, task content being the most important factor affecting model set completion. A “Minimal Completion” strategy is proposed to operate in the absence of thematic content. The experiments also falsify the long-held assumption that conditionals with negative antecedents are always interpreted as their disjunctive equivalents. This raises doubts about the mental models explanation for matching bias in conditional reasoning.

Causal and noncausal conditionals: An integrated model of interpretation and reasoning

We present an integrated model for the understanding of and the reasoning from conditional statements. Central assumptions from several approaches are integrated into a causal path model. According to the model, the cognitive availability of exceptions to a conditional reduces the subjective conditional probability of the consequent, given the antecedent. This conditional probability determines people's degree of belief in the conditional, which in turn affects their willingness to accept logically valid inferences. In addition to this indirect pathway, the model contains a direct pathway: Availability of exceptional situations directly reduces the endorsement of valid inferences. We tested the integrated model with three experiments using conditional statements embedded in pseudonaturalistic cover stories. An explicitly mentioned causal link between antecedent and consequent was either present (causal conditionals) or absent (arbitrary conditionals). The model was supported for the causal but not for the arbitrary conditional statements.

Residential placement and quality of life for adults with severe autism spectrum disorders and severe-to-profound intellectual disabilities

Purpose

The purpose of this paper is to evaluate the relationship between some main characteristics of different living arrangements and the quality of life (QoL) of their users with severe intellectual disability and low-functioning autism spectrum disorders.

Design/methodology/approach

Study participants were assessed for ASD severity through the Childhood Autism Rating Scale or the Vineland Adaptive Behavior Scales (VABS): for behavioral problems with the aberrant behavior checklist (ABC); for perception of efficacy and satisfaction with care, through an adapted Visual Analogue Scale; and for QoL with the QoL inventory in residential environments (validated in French as Inventaire de la Qualité de Vie en Milieu Résidentiel). Because the goal was to define a “residential profile (RP),” the authors evaluated each participating residence with the Working Methods Scale and the questionnaire on residential parameters.

Findings

The RP allowed for the classification of the residences into three clusters. The authors found no clear relationship between QoL and the RP clusters, but the authors found the RP clusters to be significantly correlated with ABC factors F1 (irritability, agitation, crying) and F2 (lethargy, social withdrawal), and VABS scores for living, socialization, and motor skills.

Originality/value

RPs were more strongly correlated with ABC items and the ability to cope with everyday life than with QoL. The authors hypothesize that RP is correlated with both aberrant behavior and the autonomy of residents and that QoL remains relatively stable. Therefore, RP is correlated with the status of the residents; however, this appears not to be correlated with their QoL.

Reasoning strategies modulate gender differences in emotion processing

The dual strategy model of reasoning has proposed that people's reasoning can be understood asa combination of two different ways of processing information related to problem premises: a counterexample strategy that examines information for explicit potential counterexamples and a statistical strategy that uses associative access to generate a likelihood estimate of putative conclusions. Previous studies have examined this model in the context of basic conditional reasoning tasks. However, the information processing distinction that underlies the dual strategy model can be seen asa basic description of differences in reasoning (similar to that described by many general dual process models of reasoning). In two studies, we examine how these differences in reasoning strategy may relate to processing very different information, specifically we focus on previously observed gender differences in processing negative emotions. Study 1 examined the intensity of emotional reactions to a film clip inducing primarily negative emotions. Study 2 examined the speed at which participants determine the emotional valence of sequences of negative images. In both studies, no gender differences were observed among participants using a counterexample strategy. Among participants using a statistical strategy, females produce significantly stronger emotional reactions than males (in Study 1) and were faster to recognize the valence of negative images than were males (in Study 2). Results show that the processing distinction underlying the dual strategy model of reasoning generalizes to the processing of emotions.

Agents and Patients in Physical Settings: Linguistic Cues Affect the Assignment of Causality in German and Tongan

Linguistic cues may be considered a potent tool for focusing attention on causes or effects. In this paper, we explore how different cues affect causal assignments in German and Tongan. From a larger screening study, two parts are reported here: Part 1 dealt with syntactic variations, including word order (agent vs. patient in first/subject position) and case marking (e.g., as ergative vs. non-ergative in Tongan) depending on verb type (transitive vs. intransitive). For two physical settings (wood floating on water and a man breaking a glass), participants assigned causality to the two entities involved. In the floating setting, speakers of the two languages were sensitive to syntactic variations, but differed in the entity regarded as causative. In the breaking setting, the human agent was uniformly regarded as causative. Part 2 dealt with implicit verb causality. Participants assigned causality to subject or object of 16 verbs presented in minimal social scenarios. In German, all verbs showed a subject (agent) focus; in Tongan, the focus depended on the verb; and for nine verbs, the focus differed across languages. In conclusion, we discuss the question of domain-specificity of causal cognition, the role of the ergative as causal marker, and more general differences between languages.

Utilitarian Moral Judgment Exclusively Coheres with Inference from Is to Ought

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 from descriptive premises (is-ought inference). Participants were presented with vignettes that allowed either deontological or utilitarian choice, and asked to draw a range of deontic conclusions, as well as judge the overall moral rightness of each choice separately. We predicted and found a selective defeasibility pattern, in which manipulations that suppressed deontic introduction also suppressed utilitarian moral judgment, but had little effect on deontological moral judgment. Thus, deontic introduction coheres with utilitarian moral judgment almost exclusively. We suggest a family of norm-generating informal inferences, in which normative conclusions are drawn from descriptive (although value-laden) premises. This family includes deontic introduction and utilitarian moral judgment as well as other informal inferences. We conclude with a call for greater integration of research in moral judgment and research into deontic reasoning and informal inference.

Interactions between inferential strategies and belief bias

The dual strategy model of reasoning proposed by Verschueren, Schaeken, and d'Ydewalle (Thinking & Reasoning, 11(3), 239-278, 2005a; Memory & Cognition, 33(1), 107-119, 2005b) suggests that people can use either a statistical or a counterexample-based strategy to make deductive inferences. Subsequent studies have supported this distinction and investigated some properties of the two strategies. In the following, we examine the further hypothesis that reasoners using statistical strategies should be more vulnerable to the effects of conclusion belief. In each of three studies, participants were given abstract problems used to determine strategy use and three different forms of syllogism with believable and unbelievable conclusions. Responses, response times, and feeling of rightness (FOR) measures were taken. The results show that participants using a statistical strategy were more prone to the effects of conclusion belief across all three forms of reasoning. In addition, statistical reasoners took less time to make inferences than did counterexample reasoners. Patterns of variation in response times and FOR ratings between believable and unbelievable conclusions were very similar for both strategies, indicating that both statistical and counterexample reasoners were aware of conflict between conclusion belief and premise-based reasoning.

Extreme cognitions are associated with diminished ability to use disconfirming evidence

OBJECTIVES

An Integrative Cognitive Model of mood swings and bipolar disorder proposes that cognitive styles characterized by extreme self-referent appraisals of internal states (e.g., 'If I have a bad night's sleep it means that I am about to have a breakdown') interfere with mood regulation. The aim of this study is to determine whether strong endorsement of such appraisals is predicted by a diminished ability to access disconfirming counterexamples.

DESIGN

We examined whether the ability to access two different categories of counterexample (known as Disabling Conditions and Alternative Causes) would predict endorsement of extreme appraisals (measured by the Hypomanic Attitudes and Positive Predictions Inventory; HAPPI) and mania risk (measured by the Hypomanic Personality Scale; HPS).

METHOD

A non-clinical sample of 150 students completed the HAPPI, the HPS and a conditional reasoning task that indexed the ability to access Disabling Conditions and Alternative Causes. Current mood was controlled for using the Internal States Scale.

RESULTS

The ability to make use of disabling counterexamples during the reasoning task was inversely related with scores on the HAPPI (r = -.19, p < .05); participants that were less able to make use of disabling counterexamples endorsed extreme self-referent appraisals to a greater extent. There was no association between the use of alternative cause counterexamples and the HAPPI, and no association between either measure of counterexample generation and the HPS.

CONCLUSIONS

A diminished ability to use disconfirming evidence when reasoning about the world may reinforce problematic cognitive styles such as extreme, personalized appraisals of experience, which can interfere with mood regulation.

PRACTITIONER POINTS

Problematic cognitive styles such as extreme, personalized appraisals of experience may be reinforced by the inability to produce or access evidence that disconfirms these maladaptive beliefs. This reasoning bias may be associated with cognitive styles underlying psychopathology. There may be clinical utility in exploring the use of disabler generation in psychological interventions, to help disconfirm maladaptive beliefs.

The capacity to generate alternative ideas is more important than inhibition for logical reasoning in preschool-age children

There is little consensus about the nature of logical reasoning and, equally important, about how it develops. To address this, we looked at the early origins of deductive reasoning in preschool children. We examined the contribution of two factors to the reasoning ability of very young children: inhibitory capacity and the capacity to generate alternative ideas. In a first study, a total of 32 preschool children were all given generation, inhibition, and logical reasoning measures. Logical reasoning was measured using knowledge-based premises such as "All dogs have legs," and two different inferences: modus ponens and affirmation of the consequent. Results revealed that correctly reasoning with both inferences is not related to the measure of inhibition, but is rather related to the capacity to generate alternative ideas. In a second study, 32 preschool children were given either the generation or the inhibition task before the logical reasoning measure. Results showed that receiving the generation task beforehand significantly improved logical reasoning compared to the inhibition task given beforehand. Overall, these results provide evidence for the greater importance of idea generation in the early development of logical reasoning.

Defeasible reasoning with legal conditionals

Valid conclusions can be defeated if people can think of conditions that prevent the consequent to occur although the antecedent is given. The goal of the present research was to investigate how people consider these conditions when reasoning with legal conditionals such as "If a person kills another human, then this person should be punished for manslaughter." In Experiments 1 and 2 legal conditionals were presented to participants together with exculpatory circumstances, i.e., counterexamples. The participants' task was to decide whether they would adhere to the legal conditional rule and punish the offender. Participants were either lawyers (i.e., advanced law students and graduate lawyers) or legal laypeople. We found that laypeople often ignore exculpatory circumstances and adhere to the conditional rule when offences evoked high levels of moral outrage. Lawyers did not show this effect. In Experiment 3 laypeople showed difficulties even when asked to simply imagine exculpatory circumstances for highly morally outrageous offences. Results provide new evidence for the role of emotions--like moral outrage--in the consideration of counterexamples to legal conditionals.

When will is not the same as should: The role of modals in reasoning with legal conditionals

Naïve reasoners reject logically valid conclusions from conditional rules if they can think of exceptions in which the antecedent is true, but the consequent is not. However, when reasoning with legal conditionals (e.g., "If a person kills another human, then this person should be punished for manslaughter") people hardly consider exceptions but evaluate conclusions depending on their own sense of justice. We show that participants' reluctance to consider exceptions in legal reasoning depends on the modal auxiliary used. In two experiments we phrased legal conditionals either with the modal "should" (i.e., " . . . then this person should be punished"), or with "will" (i.e., " . . . then this person will be punished") and presented them as modus ponens or modus tollens inferences. Participants had to decide whether the offender should or will be punished (modus ponens) or whether the offender indeed committed the offence (modus tollens). For modus ponens inferences phrased with "should" we replicate previous findings showing that participants select conclusions on the basis of their own sense of justice (Experiments 1 and 2). Yet, when the legal conditional is phrased with the modal "will" this effect is attenuated (Experiments 1 and 2), and exceptions are considered (Experiment 1). The modal auxiliary did not affect modus tollens inferences.

Effects of question formats on causal judgments and model evaluation

Evaluation of causal reasoning models depends on how well the subjects' causal beliefs are assessed. Elicitation of causal beliefs is determined by the experimental questions put to subjects. We examined the impact of question formats commonly used in causal reasoning research on participant's responses. The results of our experiment (Study 1) demonstrate that both the mean and homogeneity of the responses can be substantially influenced by the type of question (structure induction versus strength estimation versus prediction). Study 2A demonstrates that subjects' responses to a question requiring them to predict the effect of a candidate cause can be significantly lower and more heterogeneous than their responses to a question asking them to diagnose a cause when given an effect. Study 2B suggests that diagnostic reasoning can strongly benefit from cues relating to temporal precedence of the cause in the question. Finally, we evaluated 16 variations of recent computational models and found the model fitting was substantially influenced by the type of questions. Our results show that future research in causal reasoning should place a high priority on disentangling the effects of question formats from the effects of experimental manipulations, because that will enable comparisons between models of causal reasoning uncontaminated by method artifact.

Probability in reasoning: a developmental test on conditionals

Probabilistic theories have been claimed to constitute a new paradigm for the psychology of reasoning. A key assumption of these theories is captured by what they call the Equation, the hypothesis that the meaning of the conditional is probabilistic in nature and that the probability of If p then q is the conditional probability, in such a way that P(if p then q)=P(q|p). Using the probabilistic truth-table task in which participants are required to evaluate the probability of If p then q sentences, the present study explored the pervasiveness of the Equation through ages (from early adolescence to adulthood), types of conditionals (basic, causal, and inducements) and contents. The results reveal that the Equation is a late developmental achievement only endorsed by a narrow majority of educated adults for certain types of conditionals depending on the content they involve. Age-related changes in evaluating the probability of all the conditionals studied closely mirror the development of truth-value judgements observed in previous studies with traditional truth-table tasks. We argue that our modified mental model theory can account for this development, and hence for the findings related with the probability task, which do not consequently support the probabilistic approach of human reasoning over alternative theories.

Neural correlates of causal power judgments

Causal inference is a fundamental component of cognition and perception. Probabilistic theories of causal judgment (most notably causal Bayes networks) derive causal judgments using metrics that integrate contingency information. But human estimates typically diverge from these normative predictions. This is because human causal power judgments are typically strongly influenced by beliefs concerning underlying causal mechanisms, and because of the way knowledge is retrieved from human memory during the judgment process. Neuroimaging studies indicate that the brain distinguishes causal events from mere covariation, and also distinguishes between perceived and inferred causality. Areas involved in error prediction are also activated, implying automatic activation of possible exception cases during causal decision-making.

The empirical study of norms is just what we are missing

This paper argues that the goals people have when reasoning determine their own norms of reasoning. A radical descriptivism which avoids norms never worked for any science; nor can it work for the psychology of reasoning. Norms as we understand them are illustrated with examples from categorical syllogistic reasoning and the “new paradigm” of subjective probabilities. We argue that many formal systems are required for psychology: classical logic, non-monotonic logics, probability logics, relevance logic, and others. One of the hardest challenges is working out what goals reasoners have and choosing and tailoring the appropriate logics to model the norms those goals imply.