Effects of anonymous peer observation on adolescents' preference for immediate rewards

Research suggests that the presence of peers influences adolescent risk‐taking by increasing the perceived reward value of risky decisions. While prior work has involved observation of participants by their friends, the current study examined whether observation by an anonymous peer could elicit similarly increased reward sensitivity. Late adolescent participants completed a delay discounting task either alone or under the belief that performance was being observed from a neighboring room by an unknown viewer of the same gender and age. Even in this limited social context, participants demonstrated a significantly increased preference for smaller, immediate rewards when they believed that they were being watched. This outcome challenges several intuitive accounts of the peer effect on adolescent risk‐taking, and indicates that the peer influence on reward sensitivity during late adolescence is not dependent on familiarity with the observer. The findings have both theoretical and practical implications for our understanding of social influences on adolescents' risky behavior.     

“You Should Know Better”: Expressions of Empathy and Disregard Among Victims of Massive Social Trauma

There is a belief that victims of extreme violence should be sensitive to the suffering of others although most of the psychosocial literature points to the opposite. We examine this belief by looking at work that we have carried out on the psychosocial effects of the Holocaust and on the Palestinian-Israeli conflict. We assert that being a victim of collective violence often inhibits empathy toward others and creates continued animosity. We focus on intergenerational aspects connected to victimization and their negative impact on the expression of empathy among descendants of victims in order to explain why the sense of victimhood and justification of repeated violence is often expressed by individuals born years after the original violence took place.     

Explanation by induction?

Philosophers of mathematics commonly distinguish between explanatory and non-explanatory proofs. An important subclass of mathematical proofs are proofs by induction. Are they explanatory? This paper addresses the question, based on general principles about explanation. First, a recent argument for a negative answer is discussed and rebutted. Second, a case is made for a qualified positive take on the issue.     

An application of a Theorem of Ash to finite covers

The technique of covers is now well established in semigroup theory. The idea is, given a semigroup S, to find a semigroup having a better understood structure than that of S, and an onto morphism of a specific kind from to S. With the right conditions on , the behaviour of S is closely linked to that of . If S is finite one aims to choose a finite . The celebrated results for inverse semigroups of McAlister in the 1970s form the flagship of this theory.Weakly left quasi-ample semigroups form a quasivariety (of algebras of type(2, 1)), properly containing the classes of groups, and of inverse, left ample, and weakly left ample semigroups. We show how the existence of finite proper covers for semigroups in this quasivariety is a consequence of Ashs powerful theorem for pointlike sets. Our approach is to obtain a cover of a weakly left quasi-ample semigroup S as a subalgebra of S × G, where G is a group. It follows immediately from the fact that weakly left quasi-ample semigroups form a quasivariety, that is weakly left quasi-ample. We can then specialise our covering results to the quasivarieties of weakly left ample, and left ample semigroups. The latter have natural representations as (2, 1)-subalgebras of partial (one-one) transformations, where the unary operation takes a transformation to the identity map in the domain of . In the final part of this paper we consider representations of weakly left quasi-ample semigroups.This work was supported by the London Mathematical Society, Fundação para a Ciência e a Tecnologia, Centro de Álgebra da Universidade de Lisboa, Centro de Matemática da Universidade do Porto and projects POCTI/32440/MAT/2000 and POCTI/32817/Mat/2000 of FEDER.Special issue of Studia Logica: Algebraic Theory of Quasivarieties Presented by M. E. Adams, K. V. Adaricheva, W. Dziobiak, and A. V. Kravchenko     

Ethical Issues in Cancer Genetics: 1) Whose Information Is It?

This article presents and discusses four clinical cases that exemplify the complexity of ethical dilemmas concerning the provider's obligation to disclose or withhold genetic information from patients. Case 1: What is the responsibility of the cancer genetics provider to ensure that a positive test results is shared with distant relatives? Case 2: To ensure that results go to at-risk relatives, do we have the right to ignore the wishes of the designated next-of-kin? Case 3: Do we have the right to reveal a familial BRCA1 mutation to a patient's relative, who is at 50% risk? Case 4: Do we have an obligation to reveal that a patient is not a blood relative and therefore, not at risk to have inherited a familial mutation? These cases form the basis for discussing the provider's dual obligations to keeping patient confidentiality and informing patients and families about risk (i.e. duty to warn). We also provide a summary of consensus points and additional discussion questions for each case.     

Psychopharmacology's debt to experimental psychology

The role of experimental psychology in the development of psychopharmacology has largely been ignored in recent historical accounts. In this article the authors attempt to redress that gap by outlining work in early experimental psychology that contributed significantly to the field. While psychiatrists focused on the therapeutic nature of drugs or their mimicry of psychopathology, experimental psychologists used psychoactive drugs as tools to study individual differences in normal behavior as well as to develop methodologies using behavior to study mechanisms of drug action. Experimental work by Kraepelin, Rivers, and Hollingworth was particularly important in establishing drug-screening protocols still used today. Research on nitrous oxide and on the effects of drug combinations is discussed to illustrate the importance of experimental psychology to psychopharmacology.     

Factors influencing adolescents' decisions to engage in risk-taking behavior

Few studies have assessed adolescent risk-taking from a decision-making perspective while also looking at sensation-seeking and locus of control. In this study, 171 older adolescents completed a risk-taking inventory to measure risk involvement. Sensation-seeking and locus of control, as well as perceived benefits and costs, were assessed to determine their effects on risk-taking. Results showed that perceived risks affected risk-taking more significantly than did perceived benefits. Higher sensation-seeking tendencies were affiliated with more risk-taking. Locus of control was not related to risk-taking.     

Cognitive and affective development in adolescence

Questions about the nature of normative and atypical development in adolescence have taken on special significance in the last few years, as scientists have begun to recast old portraits of adolescent behavior in the light of new knowledge about brain development. Adolescence is often a period of especially heightened vulnerability as a consequence of potential disjunctions between developing brain, behavioral and cognitive systems that mature along different timetables and under the control of both common and independent biological processes. Taken together, these developments reinforce the emerging understanding of adolescence as a critical or sensitive period for a reorganization of regulatory systems, a reorganization that is fraught with both risks and opportunities.