Naive probability: a mental model theory of extensional reasoning

This article outlines a theory of naive probability. According to the theory, individuals who are unfamiliar with the probability calculus can infer the probabilities of events in an extensional way: They construct mental models of what is true in the various possibilities. Each model represents an equiprobable alternative unless individuals have beliefs to the contrary, in which case some models will have higher probabilities than others. The probability of an event depends on the proportion of models in which it occurs. The theory predicts several phenomena of reasoning about absolute probabilities, including typical biases. It correctly predicts certain cognitive illusions in inferences about relative probabilities. It accommodates reasoning based on numerical premises, and it explains how naive reasoners can infer posterior probabilities without relying on Bayes's theorem. Finally, it dispels some common misconceptions of probabilistic reasoning.     

Judgements of Deontic Relevance in Reasoning: A Reply to Jackson and Griggs

Facilitation on abstract versions of the selection task can be produced by deontic content. Jackson and Griggs (1990) claimed that this finding depends on the presence of an explicit negative on the not-q card. We hypothesized that the removal of the explicit negative from this card made its deontic status ambiguous. Experiment 1 demonstrated that a not-q card presenting implicit negative is not selected, and most subjects select the only card that appears to be relevant from a deontic point of view (i.e. the p card). Experiments 2 and 3 showed that the presence of the explicit negative on the not-q card is not necessary for producing facilitation, provided that the form of this card makes it clear that the not-q individual is a potential violator. Experiment 4 showed that a high success rate can be obtained even with a not-q card presenting an implicit negative. The results are discussed in terms of the specificity of reasoning in the deontic domain.     

On the use of microwave radar devices in chronobiology studies: An application with<Emphasis Type="Italic">Periplaneta americana</Emphasis>

Modified motion detectors can be used to monitor locomotor activity and measure endogenous rhythms. Although these devices can help monitor insects in their home cages, the small size of the animals requires a very short wavelength detector. We modified a commercial microwave-based detection device, connected the detector’s output to the digital input of a computer, and validated the device by recording circadian and ultradian rhythms.Periplaneta americana were housed in individual cages, and their activity was monitored at 18°C and subsequently at 28°C in constant darkness. Time series were analyzed by a discrete Fourier transform and a chi-square periodogram. Q₁₀ values and the circadian free-running period confirmed the data reported in the literature, validating the apparatus. Moreover, the spectral analysis and periodogram revealed the presence of ultradian rhythmicity in the range of 1–8 h.     

Embodied simulation: From neurons to phenomenal experience

The same neural structures involved in the unconscious modeling of our acting body in space also contribute to our awareness of the lived body and of the objects that the world contains. Neuroscientific research also shows that there are neural mechanisms mediating between the multi-level personal experience we entertain of our lived body, and the implicit certainties we simultaneously hold about others. Such personal and body-related experiential knowledge enables us to understand the actions performed by others, and to directly decode the emotions and sensations they experience. A common functional mechanism is at the basis of both body awareness and basic forms of social understanding: embodied simulation. It will be shown that the present proposal is consistent with some of the perspectives offered by phenomenology.     

Use or misuse of the selection task? Rejoinder to Fiddick,Cosmides, and Tooby

Sperber, Cara, and Girotto (Cognition 52 (1995) 3) argued that, in Wason's selection task, relevance-guided comprehension processes tend to determine participants' performance and pre-empt the use of other inferential capacities. Because of this, the value of the selection task as a tool for studying human inference has been grossly overestimated. Fiddick, Cosmides, and Tooby (Cognition 77 (2000) 1) argued against Sperber et al. that specialized inferential mechanisms, in particular the "social contract algorithm" hypothesized by Cosmides (Cognition 31 (1989) 187), pre-empt more general comprehension abilities, making the selection task a useful tool after all. We rebut this argument. We argue and illustrate with two new experiments, that Fiddick et al. mix the true Wason selection task with a trivially simple categorization task superficially similar to the Wason task, yielding methodologically flawed evidence. We conclude that the extensive use of various kinds of selection tasks in the psychology of reasoning has been quite counter-productive and should be discontinued.     

The disposition-situation debate and research on aggression

Person-situation interaction is considered in the light of a redefinition of the notions of consistency, stability, coherence, and specificity. A research program able to combine the study of individual differences with experimental research in a developmental perspective is recommended. Findings from research on aggression are presented to support this approach.     

Mental representation and hypothetico-deductive reasoning: The case of the THOG problem

Summary This article reports three experiments that deal with the source of the difficulty of Wason's (1977) THOG problem. The solution of this problem demands both the postulation of hypotheses and a combinatorial analysis of their consequences. Experiment 1 showed that the generation of the hypotheses is not in itself sufficient to solve the problem. Experiment 2 showed that a version presenting a plausible context for separating the level of data from that of hypotheses produced a better performance than both the original abstract version and a thematic version lacking the plausible context separating the levels. Experiment 3 gave evidence that this context can produce facilitation even with the geometric material of the classic version. This experiment also showed that a pictorial presentation of data and a verbal presentation of hypotheses affect performance negatively. The results demonstrate the role of problem representation in problem solving, and, in particular, the role of homogeneity in representing data and hypotheses in hypothetico-deductive reasoning.     

Trait congruence in the study of the cognitive consequences of emotional arousal

This study investigated the possible influence of mood and emotional vulnerability on recall. Mood was induced by projecting highly emotionally laden slides. In the first experiment, 64 female subjects, rated low or high on emotional vulnerability, were tested on recall of mood-congruent, mood-incongruent and neutral words, under mood induction and non-mood induction conditions. Emotionally low-vulnerable subjects recalled more mood-congruent than mood-incongruent words in the mood induction condition, whereas the opposite was the case in the non-mood induction condition. Highly vulnerable subjects recalled more mood-congruent than mood-incongruent words in the non-mood induction condition and fewer mood-congruent words in the mood induction compared with non-mood induction condition. The results are discussed in terms of ‘mood congruence’ (to explain low-vulnerable (LV) subjects' performance) and in terms of ‘trait congruence’ (to explain highly-vulnerable (HV) subjects' performance). In a second experiment, which investigated LV and HV subjects' galvanic skin responses to highly- and low-emotionally laden slides, the highest values were those for HV subjects when exposed to emotional slides. The different activation of LV and HV subjects led us to reconsider previous reasoning regarding mood congruence and trait congruence in the light of the inverted U theory.     

Hermeneutics and the Philosophy of Medicine: Hans-Georg Gadamer'sPlatonic Metaphor

Taking as our starting point Plato'smetaphor of the doctor as philosopher we reflect on some aspects of the epistemological status of medicine. The framework to this paper is the hermeneutics of Hans-Georg Gadamer which shows the paradoxical nature of Western medicine in choosing the body-object as its investigative starting point, while in actual fact dealing with subjects. Gadamer proposes a model of medicine as the art of understanding and dialogue, which is capable of bringing together its various constituent parts, i.e. knowledge, knowing how to do and knowing how to be, in medical practice and in the physician'straining. The paper concludes with a brief discussion of the dyadic figure of the physician as Platonic master of the living totality and wounded healer, capable of activating the patient'sself-healing capacity.     

Intellectual ability, learning style, personality, achievement motivation and academic success of psychology students in higher education

This study is directed towards an integration of intellectual ability, learning style, personality and achievement motivation as predictors of academic success in higher education. Correlational analyses partly confirmed and partly disconfirmed our expectations in a sample of 409 first-year psychology students. Consistent with the literature, intellectual ability and achievement motivation were associated positively with academic success. For the meaning directed, reproduction directed and application directed learning style, no positive association with academic success could be detected. The undirected learning style, however, appeared to be a consistent negative predictor. For the Big Five personality factors (extraversion, agreeableness, conscientiousness, neuroticism and openness to experience), a consistent, positive association for conscientiousness with academic success was found. The very first examination at the university came out as the most important predictor for academic success, even after two and three years of study. The implications of the results are discussed in relation to the literature and the policy of the Dutch Ministry of Education.