Causal knowledge and categories: the effects of causal beliefs on categorization, induction, and similarity

Despite the recent interest in the theoretical knowledge embedded in human representations of categories, little research has systematically manipulated the structure of such knowledge. Across four experiments this study assessed the effects of interattribute causal laws on a number of category-based judgments. The authors found that (a) any attribute occupying a central position in a network of causal relationships comes to dominate category membership, (b) combinations of attribute values are important to category membership to the extent they jointly confirm or violate the causal laws, and (c) the presence of causal knowledge affects the induction of new properties to the category. These effects were a result of the causal laws, rather than the empirical correlations produced by those laws. Implications for the doctrine of psychological essentialism, similarity-based models of categorization, and the representation of causal knowledge are discussed.     

Calibration trumps confidence as a basis for witness credibility

Confident witnesses are deemed more credible than unconfident ones, and accurate witnesses are deemed more credible than inaccurate ones. But are those effects independent? Two experiments show that errors in testimony damage the overall credibility of witnesses who were confident about the erroneous testimony more than that of witnesses who were not confident about it. Furthermore, after making an error, less confident witnesses may appear more credible than more confident ones. Our interpretation of these results is that people make inferences about source calibration when evaluating testimony and other social communication.     

Order in Choice: Effects of Serial Position on Preferences

ABSTRACT— When several choice options are sampled one at a time in a sequence and a single choice of the best option is made at the end of the sequence, which location in the sequence is chosen most often? We report a large-scale experiment that assessed tasting preferences in choice sets of two, three, four, or five wines. We found a large primacy effect—the first wine had a large advantage in the end-of-sequence choice. We also found that participants who were knowledgeable about wines showed a recency effect in the longer sequences. We conclude with a process model that explains our findings.     

Linking cause and solution: Predicting support for poverty alleviation proposals

There are multiple alternative proposals for alleviating poverty, but unless these receive public support they are unlikely to be implemented. Drawing on Feagin's work, this research predicted support for different poverty alleviation proposals among Australians based on individual characteristics and attitudes, including explanations for poverty. Overall, participants (N = 526) favoured the minimum income proposal (traditional welfare) significantly more than the guaranteed jobs or equal income proposals. The results indicated differences in predictors of support for each proposal, but structural causes of poverty had the most consistent effect across all three. Other variables included gender, age, having received welfare, self‐reported social class, self‐reported financial situation, egalitarianism, conservatism, and support for individualistic explanations for poverty. The results suggested that Australians prefer traditional welfare‐style measures to alleviate poverty, compared to the other proposals examined here. Support for all proposals, however, was predicated on people's beliefs being consistent with those underlying the proposal. Those interested in implementing more radical solutions to address poverty need to emphasise the relations between the causes of poverty and the solutions to it in order to increase public support.     

Explanations determine the impact of information on financial investment judgments

Previous research has shown that some types of judgments are influenced by the results of an explanation‐seeking comprehension process. The present experiments investigated novice investors' stock price forecasts and investment decisions. Information presented in a narrative story order was hypothesized to promote the construction of a coherent mental representation that would affect how information was interpreted and subsequently used to predict stock price changes. The results showed that outcome information had a distinctively high impact, but only when the information was read in story order. These results imply that presentation order affects the mental representation of evidence relevant to the forecast, and the form of that mental representation moderates the impact of individual pieces of information on the ultimate judgment. Copyright © 2005 John Wiley & Sons, Ltd.     

Individuation and reference in memory: Proper names and definite descriptions

A theory is presented which assumes that individuals are represented by unique nodes in memory. To test the theory, simple facts were predicated of an individual person. Some facts referred to him by proper name, and other facts by his profession. In a before condition, subjects learned that the profession and name referred to the same individual before learning the facts, while in an after condition, they learned the identity after learning the facts. Subsequent to learning the facts and identities, subjects verified sentences based on what they had learned. Verification latencies indicated that in the before condition, one memory node was created to represent the individual, but two nodes were set up in the after condition. Assymmetries between proper names and professions indicate that the two types of referring expressions are treated differently in long-term memory.     

Perceived causality as a cue to temporal distance

The three experiments reported show that judgments of elapsed time between events depend on perceived causal relations between the events. Participants judged pairs of causally related events to occur closer together in time than pairs of causally unrelated events that were separated by the same actual time interval. The causality-time relationship was first demonstrated for time judgments about historical events. Causally related events were judged to be significantly closer together in time than causally unrelated events. In two subsequent experiments, perceived causality was manipulated by providing expert information and by asking the participants themselves to imagine causal relationships between the to-be-judged events. Again, substantial and reliable effects of perceived causality were obtained. Our results suggest that people use strength of perceived causality as a cue to infer temporal distance.     

La evaluación de la evidencia en la toma de decisiones complejas

Resumen

En esta investigación se analiza el papel de cómo se representa la evidencia en el proceso de decisión de un miembro de un jurado. Se presenta asimismo un modelo que incorpora una primera etapa inicial de procesamiento en la que se generan ciertas representaciones cognitivas de la evidencia bajo la forma de una historia. Esta etapa inicial viene seguida del cálculo de la decisión evaluando la bondad de ajuste de la representación de la evidencia (la historia) a los distintos tipos de veredicto. Cada uno de los sujetos, extraídos de listas de jurados, proporcionaba su veredicto sobre un juicio de asesinato que se presentaba filmado. A través de una entrevista en profundidad con cada uno de los jurados se obtenían los datos necesarios para el análisis de sus representaciones cognitivas de la evidencia del caso, de los tipos de veredicto presentados en las instrucciones del juez, y de los procedimientos que hubieron de seguir de acuerdo con la ley para llegar a un veredicto final. De acuerdo con nuestra hipótesis, hallamos que la evidencia del juicio se representaba bajo la forma de una historia. Además, las diferencias que se obtuvieron entre jurados respecto de sus representaciones cognitivas se correlacionaron con sus veredictos, aunque otros aspectos del proceso de decisión se correlacionaran (las representaciones de los distintos tipos de veredicto, y la aplicación de las instrucciones respecto del procedimiento para la evaluación de las pruebas). Terminamos concluyendo que una teoría apropiada de la toma de decisiones debe prestar atención a aquellos aspectos cognitivos de la tarea, como por ejemplo los que afectan a la representación de la evidencia.     

Developmental surface dyslexia and dysgraphia: An orthographic processing impairment

This study presents a detailed investigation of a young man in his early twenties who has suffered from a severe spelling impairment since childhood, and currently has a spelling age of only 9 years and 2 months. In contrast with the developmental phonological dyslexics reported by Campbell and Butterworth (1985) and Funnell and Davison (1989), his performance on tests of phonological awareness is good. In addition, he can read and spell non-words competently and, unlike normal 9-year-old children, virtually all of his spelling errors are phonologically appropriate. Further analysis of these errors reveals that he has knowledge of many of the different ways in which a given phoneme can be written, and that he uses phoneme-to-grapheme correspondences at the end of a word that are different from those he uses earlier in a word. However, he finds it difficult to spell words that contain uncommon phoneme-to-grapheme correspondences, which is compatible with the view that he has not developed an orthographic spelling lexicon. Although his oral reading of words is prompt and generally accurate, analysis of his lexical decision performance and the way that he defines homophones indicate that he does not have fully specified lexical entries available for reading either. We suggest that he suffers from a general orthographic processing deficit, and relies instead upon the combination of sub-lexical phonology and a lexicon that contains only partial information about way in which words are spelt. This leads to reasonably competent reading, even of many irregular words, but produces very poor spelling. It is argued that qualitatively different types of developmental dyslexia do genuinely exist, but that reading impairments are likely to be much more pronounced in children who have a phonological rather than an orthographic processing deficit.