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951.
The key aim of the present research was to study the “functionality” of two global variables in the Olweus Bully/Victim Questionnaire and to examine the appropriateness of different cutoff points of these variables for prevalence estimation. Several empirical and conceptual analyses strongly attested to the functionality of the two selected variables in terms of construct validity and selected measurement properties. Similarly, a number of analyses indicated that (having been bullied/having bullied other students) “2 or 3 times a month” was a reasonable and useful lower‐bound cutoff point. With this cutoff point, “involved” students, victims, and bullies differed very markedly and in clearly different ways from “non‐involved” students in conceptually related variables. Prevalence estimates derived in this way can be conveniently obtained, have a reasonably well‐defined meaning, can be easily understood by users, and can be reproduced unambiguously by different researchers/administrators and at different times. An important background for the article is the fact that several common methods, including peer nominations, are not well suited for prevalence estimation. Prevalence data for victims, bullies, and bully‐victims are also presented. All data were derived from the New Bergen Project Against Bullying, comprising a sample of 5,171 students from 37 schools in the town community of Bergen, Norway. At the time of the data collection, the spring of 1997, the 2,544 girls and 2,627 boys were in grades 5 through 9, with modal ages of 11 through 15 years. Aggr. Behav. 29:239–268, 2003. © 2003 Wiley‐Liss, Inc.  相似文献   
952.
The effects of testosterone propionate, an anabolic‐androgenic steroid, on the behavior displayed during a social encounter by gonadally intact male mice were investigated. Animals were distributed into three groups according to their attack latency in a pre‐screening test (high‐, moderate‐, and low‐ attacking mice) and each group received weekly injections of 60 or 120 mg/kg of testosterone or sesame oil for 10 weeks. Behavioral tests were then carried out. Afterwards, organs were weighed and blood samples collected in order to obtain hormonal data. Treatment had a differential impact on attack in the three groups of animals. Only the high‐attacking testosterone‐treated mice showed lower total duration of attack than their controls. Those that received 60 mg/kg spent more time exhibiting exploratory behaviors. As an index of the anabolic activity of the drug, all testosterone‐treated mice had heavier kidneys and, as an index of the androgenic activity of testosterone propionate, they had heavier seminal vesicles, lighter testes, and showed higher testosterone levels in a dose‐dependent way than their controls. Hence, the effect of treatment on peripheral physiological parameters was similar in all three groups whereas behavioral effects differed depending on basal aggressiveness, considered a characteristic of coping style. Aggr. Behav. 29:173–189, 2003. © 2003 Wiley‐Liss, Inc.  相似文献   
953.
This paper examines the occurrence of framing effects when more thought is given to problems. In Study 1, participants were presented with one of two frames of several decision problems. Participants' Need for Cognition (NC) scores were obtained, and half the participants were asked to justify their choices. Substantial framing effects were observed, but the amount of thought purportedly given to a problem, whether manipulated by justification elicitation or measured by NC scores, did not reduce the incidence of framing effects. In Study 2, participants responded to both frames of problems in a within‐subjects design. Again, NC scores were unrelated to responses on the first frame encountered. However, high‐NC, compared to low‐NC, participants were more consistent across frames of a problem. More thought, as indexed here, does not reduce the proclivity to be framed, but does promote adherence to normative principles when the applicability of those principles is detectable. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
954.
Recent decision‐making research claims to establish that, in violation of Savage's normative sure‐thing principle, individuals often wait to acquire noninstrumental information and subsequently base their decisions upon this information. The current research suggests that characterizing individuals as pursuing noninstrumental or useless information may be overstated. Through a series of experiments we establish, first, that many people choose to wait, even when waiting provides no additional information at all. Second, the longer people are allowed to wait before having to decide, the more people prefer to wait rather than decide immediately. Third, those individuals who choose to wait are the ones less confident about committing themselves to a decision. For them, the benefit from waiting may be especially valuable by allowing them to come to terms with a less‐than‐ideal decision. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
955.
Episodic memory and the hippocampus: it's about time   总被引:2,自引:0,他引:2  
Several recent studies have sought to develop animal models of episodic memory, the capacity to recollect unique personal experiences. However, these studies have not yet provided unambiguous evidence that this capacity is based on recollection of the learning episodes. A recent study that examined memory for the ordering of events within unique experiences, and demonstrated a critical and selective role for the hippocampus, suggests a new and promising model for neurobiological analyses of episodic memory.  相似文献   
956.
Anticipating the future has a decided evolutionary advantage, and researchers have found many evolutionarily conserved mechanisms by which humans and animals learn to predict future events. Researchers often study such learned behavior using conditioning experiments. The marine snail Aplysia has been at the forefront of research into the cellular and molecular mechanisms of classical conditioning. Recently, Aplysia has also gained a reputation as a valuable model system for operant reward learning. Its feeding behavior can be operantly conditioned in the intact animal as well as in reduced preparations of the nervous system. The reward signal relies on dopamine transmission and acts in conjunction with activity in an identified neuron (B51) to bring about operant memory.  相似文献   
957.
The simplicity principle in human concept learning   总被引:1,自引:0,他引:1  
How do we learn concepts and categories from examples? Part of the answer might be that we induce the simplest category consistent with a given set of example objects. This seemingly obvious idea, akin to simplicity principles in many fields, plays surprisingly little role in contemporary theories of concept learning, which are mostly based on the storage of exemplars, and avoid summarization or overt abstraction of any kind. This article reviews some evidence that complexity minimization does indeed play a central role in human concept learning. The chief finding is that subjects' ability to learn concepts depends heavily on the concepts' intrinsic complexity; more complex concepts are more difficult to learn. This pervasive effect suggests, contrary to exemplar theories, that concept learning critically involves the extraction of a simplified or abstracted generalization from examples.  相似文献   
958.
Differences in the drug use characteristics and psychosocial variables in the use and non‐use of ecstasy within 845 16–25 year‐olds in the UK was examined. Based on levels of ecstasy use and intentions, two groups of non‐users (resistant and vulnerable), three groups of users (light, moderate and heavy) and an ex‐user group were identified. It was found that there is predictive utility in this way of expanding the widely employed ‘user versus non‐user’ dichotomy. Resistant non‐users were more likely to be younger, female, and were characterized by lower levels of use of four other drugs (amphetamine, cannabis, cocaine and LSD). Those ‘at risk’ of using ecstasy reported more frequent use of amphetamine, LSD, and cannabis than resistant non‐users. Heavy user groups reported using amphetamine, cocaine and LSD more frequently than all the other groups. Having ecstasy using friends increased the odds of being an ‘at risk’ non‐user or an ecstasy user. Normative influence also differentiated between the three user groups (light, moderate, and heavy). Beliefs about ecstasy use being immoral, ecstasy offers being difficult to resist, ecstasy use making one feel guilty and ecstasy being readily available differentiated between user and non‐user groups. These factors could usefully inform the content of health education materials designed to change ecstasy use. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
959.
Erna was one of the child patients treated by Melanie Klein in Berlin, employing her recently discovered play technique. Since Erna died in Chile, the authors considered the IPA Congress in Santiago an opportunity to present a paper as a homage both to Erna and, especially, to Klein. She learned much from that very disturbed child, which she later used to sustain the ongoing development of her theories. The paper explores biographic data relevant to understanding both the case and the theories. It analyses the case material to follow Klein in the discovery and the handling of the child's transference and the harsh expressions of hate, jealousy and envy, which are brought in, with sad consequences, by strong persecutory feelings. Klein's comparison of this case with that of Freud's Wolf-man is also considered, mostly to show that the similarities were less than originally claimed, and that Klein, perhaps, was introducing a theoretic shift which led her technique to gradually change from ' Nachträglichkeit ' to the 'signification-resignification' pair, akin to Strachey's concept of the mutative interpretation. Lastly, the comprehension of Erna's strong psychotic traits and the links with later developments of the theory on psychosis are studied.  相似文献   
960.
The author explores the concept of reality‐testing as a means of assessing the relationship with reality that prevails in dream and in virtual reality. Based on a model developed by Jean Laplanche, she compares these activities in detail in order to determine their respective independence from the function of reality‐testing. By carefully examining the concept of hallucination in the writings of Freud and Daniel Dennett, the author seeks to pinpoint the specific modalities of interaction between perceptions, ideas, wishes and actions that converge in the ‘belief’ and in the ‘sense of reality’. The paper's main thesis consists of the distinction that it draws between immediacy‐testing and reality‐testing, with the further argument that this distinction not only dissipates the conceptual vagueness that generally surrounds the latter of the two concepts but also that it promotes a more precise analysis of the function of reality in dream and in virtual reality.  相似文献   
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