Trust and commitment in the United States and Japan

A distinction is proposed betweentrust as a cognitive bias in the evaluation of incomplete information about the (potential) interaction partner andassurance as a perception of the incentive structure that leads the interaction partner to act cooperatively. It is hypothesized that trust in this sense helps people to move out of mutually committed relations where the partner's cooperation is assured. Although commitment formation is a rather standard solution to the problems caused by social uncertainty, commitment becomes a liability rather than an asset as opportunity costs increase. Facing increasing opportunity costs, trust provides a springboard in the attempt to break psychological inertia that has been mobilized to maintain committed relations. In conjunction with an assumption that networks of mutually committed relations play a more prominent role in Japanese society than in American society, this hypothesis has been applied to predict a set of cross-national differences between the United States and Japan in the levels of trust and related factors. The results of a cross-national questionnaire survey (with 1,136 Japanese and 501 American respondents) support most of the predictions, and indicate that, in comparison to Japanese respondents, American respondents are more trusting of other people in general, consider reputation more important, and consider themselves more honest and fair. In contrast, Japanese respondents see more utility in dealing with others through personal relations.The research reported in this paper has been supported by the Institute of Nuclear Safety System, Inc. We would like to thank Professor Jyuji Misumi, the director of the Social System Research Department of the institute, and Mr. Akira Yamada, the associate director of the department, for their constant encouragement and support. We would also like to thank past attendants of the trust workshops, also supported by the institute, Professors Karen Cook, Peter Kollock, Mary Brinton, Tatsuya Kameda, Taro Kamioka, Ichiro Numazaki, Motoki Watabe, Kumiko Mori, Nahoko Hayashi, Nobuhito Jin, and Nobuyuki Takahashi. This research has been supported also by Abe Fellowship and a Ministry of Education Scientific Research Grant provided to Toshio Yamagishi.     

Reliability and validity of a Japanese version of the Eating Disorder Inventory

The rapid increase of patients with eating disorders in Japan has male necessary the reliable and valid measurement of psychological factors in eating disorders. The purpose of this study was to examine the reliability and validity of the Japanese version of the Eating Disorder Inventory. 766 females without eating disorders and 139 female patients with eating disorders responded to the Eating Attitude Test and the Eating Disorder Inventory. Principal factor extraction with promax rotation isolated 9 interpretable factors with satisfactory internal consistency (Cronbach alpha range=.74-.90). Compared with controls, patients scored significantly higher on all factors after minimizing the influence of Body Mass Index. There were strong correlations among factor scores and scores on the Eating Attitudes Test, particularly among patients. These results indicate the Eating Disorder Inventory as showing psychometrically sound internal consistency and concurrent validity.     

Does simile comprehension differ from metaphor comprehension? A functional MRI study

Since Aristotle, people have believed that metaphors and similes express the same type of figurative meaning, despite the fact that they are expressed with different sentence patterns. In contrast, recent psycholinguistic models have suggested that metaphors and similes may promote different comprehension processes. In this study, we investigated the neural substrates involved in the comprehension of metaphor and simile using functional magnetic resonance imaging (fMRI) to evaluate whether simile comprehension differs from metaphor comprehension or not. In the metaphor and simile sentence conditions, higher activation was seen in the left inferior frontal gyrus. This result suggests that the activation in both metaphor and simile conditions indicates similar patterns in the left frontal region. The results also suggest that similes elicit higher levels of activation in the medial frontal region which might be related to inference processes, whereas metaphors elicit more right-sided prefrontal activation which might be related to figurative language comprehension.     

Individualistic attitudes toward attractive rewards in older people: An experimental study using ultimatum games

This study used an ultimatum game to test the hypothesis that older individuals make more selfish offers when bargaining for highly attractive rewards, regardless of the impacts of others' responses on reward size. Both older and younger individuals separately participated in the experiment and made offers as allocators. The effects of four factors (age, certainty of the allocators' own reward depending on the recipient's response, the recipient's response, and type of rewards to be shared) on participants' offers and expectations of recipients' replies were observed. Older participants demanded higher shares for themselves than younger participants, even under the low certainty condition in the highly attractive reward scenario. Particularly in this scenario, older participants increased their portions immediately after receiving rejections. Moreover, they consistently expected the recipients to accept their offers regardless of the proposed distribution amount or bargaining conditions. It was implied that the high attractiveness of the rewards made it difficult for older individuals to predict the recipient's view of their proposals and thus contributed to them making selfish proposals.     

How might the discrepancy in the effects of perceptual variables on numerosity judgment be reconciled?

It has been claimed that a genuinely abstract numerical representation would be capable of representing the numerosity of any set of discrete elements independently of the attributes of the individual elements. In practice, however, perceptual variables, such as element size, density, and others, affect numerosity judgment. In this study, we examined how perceptual variables affect the performance of numerosity judgments under the control of factors such as amount of practice and set size. In Experiment 1, we introduced the numerosity comparison task to less experienced observers in order to examine the effect of element size and array area. In Experiment 2, we examined whether and how practice would influence precision and accuracy in numerosity comparison and demonstrated that the effects of perceptual variables mostly disappeared. In Experiment 3, we examined whether the effect of practice could transfer to the performance in different stimulus conditions. Taking the results together, we demonstrate that differences in practice might be the source of inconsistent results for perceptual variables.     

Forest chimpanzees (Pan troglodytes verus) remember the location of numerous fruit trees

It is assumed that spatial memory contributes crucially to animal cognition since animals’ habitats entail a large number of dispersed and unpredictable food sources. Spatial memory has been investigated under controlled conditions, with different species showing and different conditions leading to varying performance levels. However, the number of food sources investigated is very low compared to what exists under natural conditions, where food resources are so abundant that it is difficult to precisely identify what is available. By using a detailed botanical map containing over 12,499 trees known to be used by the Taï chimpanzees, we created virtual maps of all productive fruit trees to simulate potential strategies used by wild chimpanzees to reach resources without spatial memory. First, we simulated different assumptions concerning the chimpanzees’ preference for a particular tree species, and, second, we varied the detection field to control for the possible use of smell to detect fruiting trees. For all these assumptions, we compared simulated distance travelled, frequencies of trees visited, and revisit rates with what we actually observed in wild chimpanzees. Our results show that chimpanzees visit rare tree species more frequently, travel shorter distances to reach them, and revisit the same trees more often than if they had no spatial memory. In addition, we demonstrate that chimpanzees travel longer distances to reach resources where they will eat for longer periods of time, and revisit resources more frequently where they ate for a long period of time during their first visit. Therefore, this study shows that forest chimpanzees possess a precise spatial memory which allows them to remember the location of numerous resources and use this information to select the most attractive resources.     

Acute effects of viloxazine HCl and flurazepam when given alone and in combination on sleep EEG: A double-blind interaction study with normals

Viloxazine, an aryl-oxypropanolamine type β-adreno-receptor antagonist, has been used in the treatment of depression. In a double-blind drug interaction study with flurazepam, a commonly used benzodiazepine hypnotic, viloxazine administered alone decreased the amount of time spent in REM sleep, increased the amount of time in the “light” stages of sleep, and increased the number of transitions to awake. However, no interactive effects of the combined administration of viloxazine and flurazepam could be detected.     

Conditioning in the prediction of therapeutic outcome in depressions

Predictions of clinical responsiveness to tricyclic anti-depressants were studied in 25 depressed patients. A well-preserved external inhibition at the commencement of treatment was found to be the best single indicator of therapeutic success.