Online research in philosophy

Transitive inference (TI) plays a part in many aspects of reasoning, and is usually assessed using variants on a particular task dubbed the “IP-paradigm”. Advocates of this paradigm assume it ensures that subjects must use deduction to solve the inferential questions. The present task with 63 adults strengthened this claim by removing all possible perceptual cues and limiting as far as possible all cues from the training procedure itself. Response speed and accuracy were measured as premises were learned. Findings show that when over-training and non-logical cues are avoided, adults nevertheless reach high levels of overall performance. However, key indexes of Lexical Marking, Relative-End-Anchoring, and Symbolic Distance are largely absent or in the opposite direction to the generally accepted view at the start of training, and are present only for response time (RT) at the end of training. The widely accepted strategy of retrieval from an integrated mental representation does emerge; but only after an initial associative process and a deductive process. Regarding three comparisons critical for demonstrating deductive TI, the inference was more demanding than its antecedents both in terms of accuracy and RT, and both after initial and final training. Existing theories of TI account for some of these findings, but what is required is a theory accommodating them all.

I assessed change in students’ moral reasoning following five 75-min classes on business ethics and two assignments utilizing a novel pedagogical approach designed to foster ethical reasoning skills. To minimize threats to validity present in previous studies, an untreated control group design with pre- and post-training measures was used. Training (n = 114) and control (n = 76) groups comprised freshmen business majors who completed the Defining Issues Test before and after the training. Results showed that, controlling for pre-training levels of moral reasoning, students in the training group demonstrated higher levels of post-training principled moral judgment than students in the control group.

Matching bias refers to the non-normative performance that occurs when elements mentioned in a rule do not correspond with those in a test item (e.g., consider the double mismatch between the rule If there is a not a T on the card then there is not a 4 and a card showing H6 ). One aim of the present work is to capture matching bias via reaction times as participants carry out truth-table evaluation tasks. Experiment 1 requires participants to verify conditional rules, and Experiment 2 to falsify them as the paradigm (a) employs four types of conditional sentences that systematically rotate negatives in the antecedent and consequent; and (b) presents predominantly cases having true antecedents. These experiments reveal that mismatching is linked to higher rates of incorrect responses and slower evaluation times. A second aim is to investigate the way not is processed. We compare a narrow view of negations, which argues that negation only denies information (e.g., not-T only says there is no T), to a search for alternatives view, which says that negations function to prime appropriate alternatives (e.g., not-T primes a search for other letters). Findings from both experiments support a narrow reading view.

In this paper the arguments for optimal data selection and the contrast class account of negations in the selection task and the conditional inference task are summarised, and contrasted with the matching bias approach. It is argued that the probabilistic contrast class account provides a unified, rational explanation for effects across these tasks. Moreover, there are results that are only explained by the contrast class account that are also discussed. The only major anomaly is the explicit negations effect in the selection task (Evans, Clibbens, & Rood, 1996), which it is argued may not be the result of normal interpretative processes. It is concluded that the effects of negation on human reasoning provide good evidence for the view that human reasoning processes may be rational according to a probabilistic standard.

Yama (2001) has presented an ingenious series of experiments in which he attempts to separate two accounts in the literature of the cause of "matching bias" in conditional reasoning. One account is that the bias arises from the way in which people process negations and the other is that it is due to the larger set sizes associated with negative propositions, rather than negation per se . Yama's experiments show influences of both negation and set size, from which he concludes that both factors contribute to the matching bias that is normally observed. In this note, it is argued that this conclusion is at odds with other findings in the literature, particularly those investigating implicit negation as the cause of the bias. Introducing explicit negations has been shown to remove matching bias completely and not partially, as Yama's account must predict. A possible reconciliation is proposed in terms of subtle contextual differences introduced by Yama's experiments.

The phenomenon known as matching bias consists of a tendency to see cases as relevant in logical reasoning tasks when the lexical content of a case matches that of a propositional rule, normally a conditional, which applies to that case. Matching is demonstrated by use of the negations paradigm that is by using conditionals in which the presence and absence of negative components is systematically varied. The phenomenon was first published in 1972 and the present paper reviews the history of research and theorising on the problem in the subsequent 25 years. Theories of matching bias considered include those based on several broad frameworks including the heuristic-analytic theory, the mental models theory, the theory of optimal data selection, and relevance theory as well as the specific processing-negations account. The ability of these theories to account for a range of phenomena is considered, including the effects of linguistic form, realistic content, and explicit negation on the matching bias effect. Of particular importance are recent findings showing that the bias is observable on a wider range of linguistic forms than has generally been thought, and that it is almost entirely dependent on the use of implicit negation in the logical cases to which rules are applied. The reasons for the general suppression of matching when realistic content is used are, however, unclear and a need for further research is identified here. It is concluded that matching bias is a highly robust effect which is closely connected with the problem of understanding implicit negation. Most of the theories in the literature are unable to account for at least some of the major phenomena discovered in research on the bias. The accounts that fare best are those that posit local effects of negation, including the heuristic-analytic and processing negations theories.

It has been reported as a robust effect that people are likely to select a matching case in the Wason selection task. For example, they usually select the 5 case, in the Wason selection task with the conditional "if an E, then a not-5". This was explained by the matching bias account that people are likely to regard a matching case as relevant to the truth of the conditional (Evans, 1998). However, because a positive concept usually constructs a smaller set than its negative one does (a rarity assumption), it is more effective to get information on the truth of the conditional in a positive set than in a negative set. Thus the optimal data selection account can also explain the effect. The set size of Q and matching by introducing negation were manipulated independently in four experiments. From the results it was inferred that the so-called matching bias was an amalgam of two different cognitive components-relevance judgement by matching and optimal data selection.

The processes that guide performance in Wason's selection task (WST) are still under debate. The matching bias effect in the negations paradigm and its elimination by explicit negations are central arguments against a substantial role for inferential processes. Two WST experiments were conducted in the negations paradigm to replicate the basic finding and to compare effects of implicit and explicit negations. Results revealed robust matching bias in implicit negations. In contrast to previous findings, matching bias was reduced but not eliminated in conditions using explicit negations. Model-based analyses suggest that matching bias is due to a switch towards a negative test strategy caused by negations.

The processes that guide performance in Wason's selection task (WST) are still under debate. The matching bias effect in the negations paradigm and its elimination by explicit negations are central arguments against a substantial role for inferential processes. Two WST experiments were conducted in the negations paradigm to replicate the basic finding and to compare effects of implicit and explicit negations. Results revealed robust matching bias in implicit negations. In contrast to previous findings, matching bias was reduced but not eliminated in conditions using explicit negations. Model-based analyses suggest that matching bias is due to a switch towards a negative test strategy caused by negations.

Intuitive predictions and judgements under uncertainty are often mediated by judgemental heuristics that sometimes lead to biases. Our micro-developmental study suggests that a presumption of rationality is justified for adult subjects, in so far as their systematic judgemental biases appear to be due to a specific executive-inhibition failure in working memory, and not necessarily to a lack of understanding of the fundamental principles of probability. This hypothesis was tested using an experimental procedure in which 60 adult subjects were trained to inhibit the classical conjunction bias on a frequency judgement task derived from Tversky and Kahneman's work. Pre- and post-test performance was assessed via a probability judgement task. The data indicated a training effect, suggesting that subjects traditionally labelled as "irrational" with respect to the classical rules of inductive reasoning are in fact "inefficient inhibitors". These findings are discussed in terms of a polymorphous view of rationality.