Yamagishi, Jin, and Kiyonari (1999) recently proposed an alternative account of ingroup favoritism in the minimal group experiment (MGE). According to the hypothesis, expectation of “bounded generalized reciprocity” that a generalized exchange system exists in the group is the primary source of the favoritism, not motivation for social identity. Partly replicating the Yamagishi et al. study, the current study with 73 participants added further evidence; they did not cooperate more with an ingroup partner than with an outgroup partner, if they believed that the partner did not know the participant's membership, regardless of the partner's membership. It was further shown that expectation of cooperation by the partner in itself was not enough to raise the participant's cooperation level. Based on these findings, it was concluded that ingroup favoritism found in MGE was a result of the shared group identity that triggered the definition of the situation as a group situation where a generalized exchange system existed for ingroup members.
This study examined when children are able to solve conditional reasoning problems correctly using the thinking strategy that spontaneously retrieves alternatives based on the inclusive/hierarchical relations of categories and how the strategy changes with aging. In the experiment, a total of 210 3-, 4-, 5-, 8-, 10-, 12-years-old, and adults were given the conditional reasoning problems and were also asked to justify their judgments. The result showed that 5-year-old children could solve the problems as well as the adults and they used the strategy similar to the adults, but the strategy did not necessarily continue to be used from children to adults.
This study examined the determinants of attitudes toward intergroup support. The data was collected from the participants of a simulated society game (SIMINSOC; Hirose, 1997). The global society in the game includes rich and poor regions, and the poor regions need to obtain support from rich regions for survival. One hundred and thirty-two participants were randomly assigned to either rich or poor regions and were engaged in various activities in the game. The level of ingroup identity was manipulated by facilitating group activities in some groups but no in others. Then they answered questions regarding the identification, attributions of responsibility, and attitude toward support provision. The results indicated that the identification toward the ingroup increased attribution bias. Furthermore, the identification toward the global society increased the intent to provide support among those from the rich regions. The discussion considered the importance of including intergroup variables in the attributional approach to support provision.
This study proposes a new conjoint model with orthogonal array using the notation of the structural equation modeling. It is shown that commonly available computer programs such as LISREL (Jöreskog & Sörbom, 1993) and LISCOMP (Muthen, 1984) can be used to estimate the worth values of conjoint measure and item response curves of the Rasch type and graded response type. One remarkable feature of this method is that the response curves of items that have never been used, can be constructed. The constructed distribution functions were compared with the empirical distribution functions of cross validation data. The proposed method seemed to work well, because these functions were very similar to each other.
Ellsberg's two-color problem, known as an example of ambiguity aversion, has generated a great deal of interest among many researchers. However, an unsettled question remains regarding the conditions that lead to heightened or diminished ambiguity aversion. We conducted a series of experiments, which required participants to choose between a clear and vague bet. Results showed that participants did not always prefer the clear bet, and the ratios of those who indicated ambiguity aversion varied depending on the types of ambiguity. Furthermore, ambiguity aversion consistently decreased when participants were allowed to choose the ambiguity task they would perform. These results were interpreted in terms of the pattern of second order probability distributions and illusion of control.
This study investigated the common characteristics of reasoning in the two types of hypothesis testing tasks that contain similar passive information gathering procedures; reception strategy task and hypothesis evaluation task. Twenty subjects built their own hypothesis but were not allowed to choose instances to test the hypothesis in the reception strategy task, and different 20 subjects in the hypothesis evaluation task only evaluated a hypothesis generated by another person. In addition, subjects were asked to mark instances that they thought suitable to test the hypothesis on each trial. Results showed that subjects chose negative (-H) tests in the middle or later stage of the task. Otherwise, they chose confirmative tests throughout the task. Two possible interpretations of the results were offered that (a) experiencing the false negative (-H+T) made subjects to realize the usefulness of negative testing, and (b) there was a phased shift of the selection tendency between the earlier phase of extracting a possible hypothesis to the later phase of refining it.
In experiment 1, the effect of an NMDA receptor antagonist, MK-801, on the formation of the spatial representation was investigated. The administration of 0.1mg/kg of MK-801 induced learning deficits in rats (n=10) with the Morris watermaze task. However, when rats (n=10) were pre-trained in the same task without drug treatment, and then trained in the same task in a different environment under the influence of the same amount of the drug, their performance was not impaired. The result suggests that rats treated with MK-801 can acquire a spatial representation of their environment, and that the impairment shown by the drug-treated rats without pre-training may be due to the impairment in the learning of the problem-solving strategy required for the watermaze place task. Experiment 2 examined this possibility. Rats (n=10) were pre-trained with a visual cue discrimination task without drug treatment and then trained in the place task with MK-801 (0.1mg/kg) treatment. They did not show impairment in the place task, indicating that rats treated with MK-801 can learn a new problem-solving strategy. Thus the learning deficits of MK-801-treated rats that have not been pre-trained do not seem to be due to impaired acquisition of the spatial representation or of the learning of strategy required to solve the watermaze place task.
Apparent sizes of circles in the Delboeuf figure were measured by magnitude estimation without modulus. The purpose was to investigate the Delboeuf illusion and the effect of judgment order on perceived size. Contrary to the conventional Delboeuf illusion, overestimation effects appeared for outer circles at small diameter differences. The illusory magnitude depended on the diameter ratio and diameter difference of the constituent circles. The maximum magnitude of the illusion did not always appear at the diameter ratio, 0.67 (as found before by the method of limits). The circle judged first had an assimilative effect on the apparent size of the subsequently judged circle. The time-order dependency of assimilation was more pronounced for the inner than for the outer circle. The judgment-order effect may be accounted for by the attention mechanism.
Some researchers have claimed that theory of mind or ‘mind reading’ ability, necessary for inferring the mental states of others, depends on language ability. However, previous tests of theory of mind were verbally demanding, and high correlations found might have been an artifact. This paper reports the performance of 22 children with autism, with varying degrees of dysfunction, on a test devised by Baron-Cohen, Jolliffe, Mortimore, and Robertson (1997), based on a relatively nonverbal theory of mind. The test involved inference of mental states from photographs of human eyes. Results indicated that mind reading ability was independent of language ability, general intelligence, or mental age. Test scores were, however, strongly related to the severity of autistic disorder. These results suggest both the independence of mind-reading ability from language ability and general intelligence, and a strong relationship between theory of mind deficit and the autistic disorder.
We conducted three experiments to examine the effect of spatial arrangement of test stimulus on the motion aftereffect (MAE). The adaptation and test stimuli were presented to subjects successively. Each adaptation stimulus consisted of a set of three gratings; a central stationary grating was located between the two surrounding gratings, one above and the other below respectively, which were arranged to move leftward for two minutes. The location and/or the shape of the test stimulus were varied to examine the effects of the spatial arrangement. The first and second experiments revealed that the MAE lasted longer when the surrounding gratings for the test were superimposed on those for the adaptation than when they were not superimposed. Further, the results of both experiments showed that the duration was not affected by the distance between the central grating and surrounding one. The results of the third experiment showed that the MAE lasted longer when the central grating for the test was identical with that for the adaptation than when not, and that the surrounding for the test need not to be identical with that for the adaptation. These results support Wade's hypothesis for explaining how MAE occurs.
The present study investigated how an actual action or viewing a movie of an action influences the subsequent semantic processing of a verbal phrase concerning the action (e.g., holding a bag with a hand). Forty participants made sensible/nonsensible judgments about the target phrase which were preceded by one of the four prime conditions: sustained action, stopped action, sustained viewing movie, and stopped viewing movie. A facilitatory priming effect was observed in the sustained action condition. Whereas an inhibitory effect was observed in the stopped action condition. These results suggest that the kinetic information affects on the semantic processing of a verbal phrase of action.
Klein and Loftus (1993) claimed that both trait-descriptive and autobiographical information about the self is available in memory, and that each can be addressed independently (the former is in the semantic memory system, the later is in the episodic memory system). In order to examine the validity of their claim, the conceptually-driven test on the implicit instruction was used. In Experiment 1, the self-descriptive task (“Does this word describe you?”) produced better performance than the semantic task. However, in Experiment 2, there was no difference in performance between the autobiographical task (“Can you access a personal experience?”) and the semantic task. These results were discussed in terms of a principle of transfer-appropriate processing, and it was interpreted that the difference in the results of the two experiments should support Klein and Loftus's (1993) claim.