Paul Pollard

On the conflict between logic and belief in syllogistic reasoning

Three experiments are reported that investigate the weighting attached to logic and belief in syllogistic reasoning. Substantial belief biases were observed despite controls for possible conversions of the premises. Equally substantial effects of logic were observed despite controls for two possible response biases. A consistent interaction between belief and logic was also recorded; belief bias was more marked on invalid than on valid syllogisms. In all experiments, verbal protocols were recorded and analyzed. These protocols are interpreted in some cases as providing rationalizations for prejudiced decisions and, in other cases, as reflecting a genuine process of premise to conclusion reasoning. In the latter cases, belief bias was minimal but still present. Similarly, even subjects who focus primarily on the conclusion are influenced to an extent by the logic. Thus a conflict between logic and belief is observed throughout, but at several levels of extent.

The source of belief bias effects in syllogistic reasoning

In studies of the belief bias effect in syllogistic reasoning, an interaction between logical validity and the believability of the conclusion has been found; in essence, logic has a larger effect on unbelievable than on believable conclusions. Two main explanations have been proposed for this finding. The selective scrutiny account claims that people focus on the conclusion and only engage in logical processing if this is found to be unbelievable; while the misinterpreted necessity account claims that subjects misunderstand what is meant by logical necessity and respond on the basis of believability when indeterminate syllogisms are presented. Experiments 1 and 2 compared the predictions of these two theories by examining whether the interaction would disappear if only determinate syllogisms were used. It did, thus providing strong support for the misinterpreted necessity explanation. However, the results are also consistent with a version of the mental models theory, and so Experiment 3 was carried out to compare these two explanations. The mental models theory received strong support, as it did also in the follow-up Experiments 4 and 5. It is concluded that people try to construct a mental model of the premises but, if there is a believable conclusion consistent with the first model they produce, then they fail to construct alternative models.

Debiasing by instruction: The case of belief bias

Abstract The study is concerned with the question of whether robust biases in reasoning can be reduced or eliminated by verbal instruction in principles of reasoning. Three experiments are reported in which the effect of instructions upon the belief bias effect in syllogistic reasoning is investigated. Belief bias is most clearly marked by a tendency for subjects to accept invalid conclusions which are a priori believable. Experiment 1 attempted to replicate and extend an experiment reported by Newstead, Pollard, Evans and Allen (1992). In contrast with their experiment, it was found that belief bias was maintained despite the use of augmented instructions which emphasised the principle of logical necessity. Experiment 2 provided an exact replication of the augmented instructions condition of Newstead et al., including the presence of problems with belief-neutral conclusions. Once again, significant effects of conclusion believability were found. A third experiment examined the use of elaborated instructi...

Content and context effects in reasoning

Griggs and Cox (1982) reported a phrasing of the Wason selection task that produces considerable facilitation. Two experiments are reported here that break down aspects of this problem in an attempt to determine the key to this effect. In the first experiment, it is shown that neither the content of drinks and age per se, nor the evocation of a detective set alone, is responsible. The second experiment focuses more closely on the original Griggs and Cox design and shows that neither (a) the presence of alcoholic and nonalcoholic drinks and the legal age as content in the problem, nor (b) the specific scenario of people drinking in a bar and a policeman enforcing the law, appears to be solely responsible for the effect. There is, however, some indication that the scenario may be more important than the content. Results are interpreted as indicating that for orientation toward counter-examples to be observed, the context (or scenario) of the problem must relate to a type of situation that subjects have previously experienced and for which they have learned appropriate testing behavior. The content need not be previously experienced as long as it is clearly appropriate to that general type of situation.

The Influence of Logic on Conditional Reasoning Performance

Two experiments are reported, in each of which subjects were asked to decide whether or not a number of statements, including the inverse, converse and contra-positive, followed logically from a given conditional rule of the form “if P then Q”. Rules referred to letter, number relationships, the linguistic form being manipulated by systematic negation of the antecedent and consequent components. The influence of logical validity on responses was investigated by examining differential frequencies with which inferences were drawn and by testing for consistent behaviour across inferences which depend upon the same logical principle. These analyses revealed little evidence for an influence of logic. Responses were found to be substantially influenced by a response bias, such that subjects showed a preference for agreeing with statements having affirmative antecedents and negative consequents. This finding was in part a replication of parallel findings on other inference tasks. In addition, correlational evidence suggested that subjects’ susceptibility to these biases was consistent across problems. A possible explanation of the non-logical biases, in terms of a “caution” effect, was proposed and it was argued that these, and other, findings indicate that logical validity plays little role in mediating behaviour regarding the consequent of a conditional rule.

Response bias in relational reasoning

In this study, we investigated the possibility that a response bias might be responsible for the typical pattern of responding observed when people reason about artificial relationships, especially set inclusions. Experiment 1 provided strong evidence for the proposed bias, since subjects tended to respond as if an unspecified relationship were symmetrical and increasingly intransitive over inferential distance. However, Experiment 2, using extended syllogisms, showed that not all relationships lead to such responding. Although the majority of the quantified relationships were responded to as if they were symmetrical, most were also regarded as transitive. Thus, the response bias idea, although of some interest, cannot provide a complete explanation of performance on these tasks.

Pornography and sexual aggression

This paper reviews work on the relation between pornography and sexual aggression, covering experimental research on arousal, attitudes, and laboratory aggression, and some correlational studies. The termpornography is intended to cover the materials used in the relevant research, although not all of these would necessarily be seen as “pornographic.” The main body of the review is divided between “aggressive” and “not specifically aggressive” pornography, with some consideration in the discussion of the nature of supposedly “nonaggressive” pornography. In the case of sexually aggressive pornography, a variety of undesirable effects have been observed. Males show equal sexual arousal to pornographic rape depictions and consenting intercourse depictions under certain “disinhibiting” circumstances, such as anger or depicted victim pleasure, and these disinhibitors can also produce increased laboratory aggression against female targets by males exposed to aggressive pornography. Aggressive and, to some extent, not specifically aggressive pornography have also been found to increase the endorsement of attitude statements that are supportive of sexual aggression. The paper concludes with a discussion of ethical considerations, possible psychological bases of the effects, and the question of censorship. It is concluded that although several types of materials may produce behavioral orientation toward, and/or attitudinal support for, sexual aggression, this is a function of aggression and dominance themes rather than the explicitness of the sexual cues. These themes extend beyond explicit pornography, through extremely violent stimuli that lack explicit sexual elements, to widely consumed “normal” films and reading matter.

The scripting of male and female rape

– The purpose of this paper is to investigate how male and female rape is scripted., – In total, 100 (50 male, 50 female) participants were asked to write down in their own words what they considered to be the typical rape when the victim was either an adult male or female., – Results revealed that mens and womens rape scripts did not dramatically differ, though several differences were revealed between male and female rape scripting, focussing around the gender stereotypes of men verses women., – Results are discussed in relation to gender role stereotyping and wider implications are considered.

Males acquaintance rape proclivity

The reported incidence of non-stranger rape is not uncommon, yet socially the concept remains ambiguous and largely unrecognised. A recent study found that college women reported engaging in more precautionary behaviours due to fear of stranger rape than acquaintance rape1. Furthermore, there is a tendency for people to fail to recognise non-consenting sexual intercourse following consenting pre-coital sexual activity between two ‘dating’ acquaintances as rape2. This results in what is termed as secondary victimisation. People may think date rape is trivial but, in fact, a recent study examining date rape found that there are detrimental consequences for victims, including trauma symptoms and lower sexual self-esteem than women who had not experienced date rape3. Therefore, considering the effects of date rape on its victims it is necessary to recognise non-stranger rape as a serious social problem, and expand on the relatively small amount of research conducted in the area.