Russell Revlin

The belief-bias effect in formal reasoning: the influence of knowledge on logic.

The present study examines the applicability of a rational model of categorical inference (e.g., Revlis, 1975b) to account for the apparently irrational decisions students reach on categorical syllogisms. In Experiment 1, students judged the logical validity of emotionally neutral conclusions to controversial premises. Of the reasoners’ decisions, 80% can be accounted for by the application of rational rules to their idiosyncratic encoding of the syllogistic premises. In Experiment 2, students were asked to solve syllogisms whose conclusions varied in truth value. When asked to reason about controversial, if not emotional, material, students do not suspend rational choice, but rather, their decisions are judicious ones, flowing logically from their idiosyncratic understanding of the materials reasoned about. When errors do occur, they result from an interrupt to rational processes and reflect conflict between competing goals rather than a switch to irrational decision processes.

Sensible reasoning in two tasks: Rule discovery and hypothesis evaluation

The hypothesis testing skills of undergraduates were measured in two tasks: the 2-4-6 rule discovery task in which students generate and assess hypotheses, and a hypothesis evaluation task, which requires only the assessment of hypotheses. The results of Experiments i and 2 show that the students consistently employed a disconfirmation strategy when assessing hypotheses, but employed a counterfactual inference strategy when they also were required to generate the hypotheses. The results of Experiment 3 suggest that the selection of the hypothesis testing strategy reflected a balance between the logical requirements of the task and the desirability of possible outcomes. Taken together, the findings support a more consistent picture of human rationality across tasks, and suggest alternatives to accounts of confirmation bias.

Understanding quantified categorical expressions

A model of categorical inference (Revlis, 1975b) claims that a conversion operation participates in the encoding of quantified, categorical expressions. As a consequence, a reasoner is said to interpret such sentences as “All A are B” in a way that permits it to also be the case that “All B are A.” The present study examines this conception of encoding using a sentence-picture verification task. In two experiments, students were asked to judge whether one of five possible Euler diagrams was true or false of a categorical expression (e.g., All A are B, No A are B, Some A are B, Some A are not B). Verification errors support a three-stage verification model whose major component is access to a “meaning stack” representing the progressive analysis of categorical relations; at the top of that stack is a converted reading of the input sentence. These findings have implications for current conceptions of categorical inference and semantic retrieval.

Reasoning counterfactually: Combining and rending

Counterfactual reasoning occurs when people are asked to assume for the sake of argument that a fact they previously thought was true is now false and to draw a conclusion on that basis. To accomplish this sort of reasoning requires a revising of one’s beliefs, which was simulated in the present study. Students were shown a set of statements that they were to assure themselves was consistent. They were then asked to accept a counterfactual assumption as true and reconcile resulting inconsistencies among the set of statements. In these problems, one statement is a generality (e.g.,All trees on the plaza are elms), another is a particular (e.g.,This tree is a pine), and one is a counterfactual (e.g.,Assume this tree is on the plaza). Students preferred to reconcile the inconsistency by identifying the generality as “true” and the particular as “false.” They did this more often when the assumptioncombined categories than when itdislodged categories and when real beliefs were at stake rather than arbitrary generalities. This study tested current models of inference for their ability to account for counterfactual reasoning and found the results to be consistent with natural deduction system, mental models, and conceptualintegration network approaches to everyday reasoning.

Response options and presentation format as contributors to conditional reasoning.

The present study examines whether students’ inability to solve conditional reasoning problems, shown in previous studies, is at least partially attributable to having to choose among logically incorrect response options. In two experiments, students evaluated conclusions to conditional reasoning problems where one of several response options was either the standard, Sometimes true, or the more logically appropriate, Could be true. Decision accuracy was related to the logical appropriateness of the response options available. This relationship was replicated across different problem types and formats.

Detecting Cheaters without Thinking: Testing the Automaticity of the Cheater Detection Module

Evolutionary psychologists have suggested that our brain is composed of evolved mechanisms. One extensively studied mechanism is the cheater detection module. This module would make people very good at detecting cheaters in a social exchange. A vast amount of research has illustrated performance facilitation on social contract selection tasks. This facilitation is attributed to the alleged automatic and isolated operation of the module (i.e., independent of general cognitive capacity). This study, using the selection task, tested the critical automaticity assumption in three experiments. Experiments 1 and 2 established that performance on social contract versions did not depend on cognitive capacity or age. Experiment 3 showed that experimentally burdening cognitive resources with a secondary task had no impact on performance on the social contract version. However, in all experiments, performance on a non-social contract version did depend on available cognitive capacity. Overall, findings validate the automatic and effortless nature of social exchange reasoning.

The role of similarity in deductive categorical inference

The category inclusion rule specifies that categories inherit the properties of their superordinates. For example, given thatall metals are pentavalent, it can be concluded thatall iron is pentavalent. Sloman (1998) showed that people do not fully endorse conclusions that follow from the category inclusion rule. He claims that people rely on the similarity between the premise and the conclusion categories (metals andiron), rather than applying the category inclusion rule. By allowing reasoners to rate their certainty for category relations (e.g.,iron is metal), as well as for conclusions, the present study shows that similarity has only an indirect effect on the certainty of conclusions: Reasoners are more certain that similar categories have a category inclusion relation, and this in turn affects the certainty of conclusions based on this relation.

Resolving Signals to Cohesion: Two Models of Bridging Inference.

This study employs reading time and eye‐fixation paradigms to test two models of how readers create bridging inferences to resolve signals to textual cohesion (e.g., too, as in Juan is a shortstop. Maria is athletic too). One model views bridges as stand‐alone propositions that are minimally necessary to maintain the coherence of the text. The other model views bridges as the result of a form of deduction in which the reader tacitly establishes premises that provide rational support for the bridging inferences. Students were timed as they read pairs of sentences, half of which were related by a signal to cohesion. Following each sentence pair, students verified a statement that probed verbatim recall or inference from the sentence pair. Readers’ responses to probe statements were consistent with having supplied an unstated premise in addition to the inferential bridge when reading sentences that contained a signal to cohesion but not when reading unsignaled sentences. These response measures correlate wit...

Hypothetical inference and category structure

The present experiment considers whether the internal structure of statements plays a role in the way students reason about hypothetical domains. Students were asked to assign truth values to statements to form a consistent set of relations about hypothetical situations. The statements varied in degree of structure along two dimensions: across categories organization (generality) and within-categories organization (typicality). The results show that when generalities affirm a relation, they are readily accepted as defining a domain. The addition of within-categories structure makes only a marginal contribution to decisions. In contrast, there is a semantic structure effect for generalities that deny a relation. The findings accord with a two-stage process derived from a generality coding model.

To detect or not to detect: A replication and extension of the three-stage model

When faced with a decision, people generally show a bias toward heuristic processing, even if it leads to the incorrect decision, such as in the base-rate neglect task. The crucial question is whether people know that they are biased. Recently, the three-stage model (Pennycook, Fugelsang, & Koehler, 2015) suggested that detecting this bias (conflict detection) is imperfect and a consistent source of bias because some people do not recognize that they are making biased decisions. In Experiment 1, participants completed a base-rate neglect task as replication of Pennycook et al. (2015). In Experiment 2, a conditional reasoning task was added as an extension to test the boundary conditions of the model. Results in Experiment 1 indicated that detection failures were a significant source of bias. However, results in Experiment 2 on the conditional reasoning task indicated that the three-stage model may be incompatible with a complex task such as conditional reasoning, an issue explored in detail in the General discussion.