This article reports a study carried out in order to measure how semantic factors affect reductions in the difficulty of the Chinese Ring Puzzle (CRP) that involves removing five objects according to a recursive rule. We hypothesised that semantics would guide inferences about action decision making. The study involved a comparison of problem solving for two semantic isomorphic variants of the CRP ( fish and fleas ) with problem solving for the puzzle's classic variant (the Balls and Boxes problem; Kotovsky & Simon, 1990). Our results showed that the number of moves was reduced by 47% in the fish version and by 51% in the flea version. We discuss these results in terms of semantic inferences and reductions in relational complexity. During the exploratory stage of problem solving participants discover the dependent relations between elements in the puzzle. Initially these relations are processed separately; learning involves generalising the relations within a coherent, interconnected whole that makes up the puzzle's rules. It seems that semantics make it easier for the puzzle's elements to be grouped together within coherent, meaningful wholes, which reduces relational complexity and facilitates problem solving.

Conditional information can be equally asserted in the forms if p, then q (e.g., “if I am ill, I will miss work tomorrow”) and q, if p (e.g., “I will miss work tomorrow, if I am ill”). While this type of clause order manipulation has previously been found to have no influence on the ultimate conclusions participants draw from conditional rules, we used self-paced reading to examine how it affects the real time incremental processing of everyday conditional statements. Experiment 1 revealed that clause order interacts with presuppositional congruency as readers hypothetically represent counterfactual statements. When if p, then q counterfactuals contained a presupposition that was incongruent with prior context, these statements took longer to read than when the presupposition was congruent, but for q, if p conditionals there was no such congruency effect. Experiment 2 revealed that reading times were influenced by the subjective probability of an indicative conditional regardless of clause order, with a penalty observed for low-probability statements relative to high-probability statements in both conditional clause orders. These data reveal a dissociation whereby clause order mediates the effect of suppositional congruency on reading times, but does not mediate the effect of subjective probability.

According to the “story model” a juror constructs an implicit mental model of a story telling what happened as the basis for the verdict choice. But the explicit justification of a verdict choice could take the form of a story (knowledge telling) or the form of a relational (knowledge-transforming) argument structure that brings together diverse, non-chronologically related pieces of evidence. The study investigates whether people tend towards knowledge telling or knowledge transforming, and whether use of these argument structure types are related to skilled argument and epistemic understanding. A sample of people on jury duty chose and justified verdicts in two abridged cases. Participants tended to display the same argument structure and argument skill across cases. Those using knowledge-transforming structures were more successful at the juror argument skills task and had a higher level of epistemic understanding. The discussion suggests that jurors approach their task with an epistemic orientation towards knowledge telling or knowledge transforming.

Previous research has found no consistent relationship between measures of disconfirmatory evidence, alternative hypotheses, and people's success in rule-discovery tasks. The present paper explores falsification's inductive benefit under the “context of discovery” in Wason's 2‐4‐6 task by developing a new type of alternative hypothesis, which we label the “new-perspective hypothesis”. Experiment 1 found that falsification is effective only when a new-perspective hypothesis is generated, rather than a same-perspective hypothesis. The total number of alternative hypotheses was also unrelated to rule-discovery success. Experiment 2 replicated Experiment 1 but included the addition of a different name-content task as well as two levels of task difficulty. The main findings were similar to those for Experiment 1, and the new-perspective hypothesis was observed to be most important for the difficult rule-discovery task. These results help to clarify the important ways new-perspective hypotheses and disconfirmatory evidence contribute to successful rule-discovery performance.

The behavioural analysis of normal adults solving a combinatorial game—the subtraction game—that was previously studied by Gneezy, Rustichini, and Vostroknutov (2010) allows one to identify the transition from one strategy to a novel strategy. Based on protocol analysis and debriefing, two different strategies used by participants in this task are identified and compared with behavioural measurements (reaction times, accuracy, and mouse movements). One is a (forward) exploration strategy and the other is a more complex but efficient backward induction procedure. The clear determination of the transition from the standard forward exploration strategy to a novel internally generated strategy is established by both protocol reports and behavioural measurements. It allows for the potential investigation of the underlying transition to be carried out by cognitive neuroscience methods. A set of characteristics of such transitions to internally generated novel strategies are discussed.

The Bayesian model has been used in psychology as the standard reference for the study of probability revision. In the first part of this paper we show that this traditional choice restricts the scope of the experimental investigation of revision to a stable universe. This is the case of a situation that, technically, is known as focusing. We argue that it is essential for a better understanding of human probability revision to consider another situation called updating (Katsuno & Mendelzon, 1992), in which the universe is evolving. In that case the structure of the universe has definitely been transformed and the revision message conveys information on the resulting universe. The second part of the paper presents four experiments based on the Monty Hall puzzle that aim to show that updating is a natural frame for individuals to revise their beliefs.

The discounting principle states that ‘the role of a given cause in producing a given effect is discounted if other plausible causes are present’ (Kelley, 1972, p. 8). The principle has only been tested with cases where the two explanations are of the same kind (i.e., causal explanations). However, explanations of properties of objects, people, or events often involve functions. Zebras have stripes in order to be better camouflaged. Humans have eyebrows to keep sweat from running into their eyes. Adrenaline is secreted in order to modulate fight and flight responses. Thus, what happens when we are faced with two different kinds of explanation for the same property: one functional and one causal? People evaluated explanations of properties for natural kinds and artefacts. Functional explanations were discounted in favour of causal explanations, however this was only true for properties of artefacts. The presence of an alternative explanation for properties of natural kinds did not affect the plausibility of either kind of explanation.

A study is reported testing two hypotheses about a close parallel relation between indicative conditionals, if A then B, and conditional bets, I bet you that if A then B. The first is that both the indicative conditional and the conditional bet are related to the conditional probability, P(B|A). The second is that de Finetti's three-valued truth table has psychological reality for both types of conditional—true, false, or void for indicative conditionals and win, lose, or void for conditional bets. The participants were presented with an array of chips in two different colours and two different shapes, and an indicative conditional or a conditional bet about a random chip. They had to make judgements in two conditions: either about the chances of making the indicative conditional true or false or about the chances of winning or losing the conditional bet. The observed distributions of responses in the two conditions were generally related to the conditional probability, supporting the first hypothesis. In addition, a majority of participants in further conditions chose the third option, “void”, when the antecedent of the conditional was false, supporting the second hypothesis.

When using sample data to decide whether two populations differ, laypeople attend to the difference between group means, but largely overlook within-group variability (Obrecht, Chapman, & Gelman, 2007). We show, first, that laypeople know about and use story-implied variability when making pairwise comparisons. Then we demonstrate that participants’ sensitivity to variance in a dataset is boosted when presented in a context that implies consistent variance information. Statistical data were couched in stories about electrical conductivity measurements obtained from element samples (low-variability category) or body weight measurements from samples of peoples (high-variability category). We manipulated, between participants, whether the data variance matched or mismatched the story-implied variability. Participants who received data in a matching context showed high sensitivity to variance, while those in the mismatching condition did not. Laypeople use statistical data to make reasonable inferences when those data are provided in a context that makes sense.

This individual differences study examined the relationships between three executive functions (updating, shifting, and inhibition), measured as latent variables, and performance on two cognitively demanding subtests of the Adult Decision Making Competence battery: Applying Decision Rules and Consistency in Risk Perception. Structural equation modelling showed that executive functions contribute differentially to performance in these two tasks, with Applying Decision Rules being mainly related to inhibition and Consistency in Risk Perception mainly associated to shifting. The results suggest that the successful application of decision rules requires the capacity to selectively focus attention and inhibit irrelevant (or no more relevant) stimuli. They also suggest that consistency in risk perception depends on the ability to shift between judgement contexts.