Spin and space

In this paper we will take a careful look at the well-known fact that a complete 2 rotation in three dimensional space, while leaving vectors, tensors and generally the integral representations of the rotation group unchanged, causes a sign change in the half-integral spinor representations of the rotation group. First, in a brief introduction, we review the origin of the sign change of spinors by a 2 rotation. Next, we analyze Aharonov and Susskind's (hereafter referred to as A. & S.) (1967) original proposal for detecting such a sign change and compare it with a later proposal¹ for detecting the sign change using neutron beams that are coherently split and recombined. While the A. & S. experiment is, we think, conceptually more interesting, the neutron beam experiment has actually been carried out. And finally, we discuss the philosophical significance of the rotationally induced spinor sign change.On leave from the Department of Philosophy, Fordham University.     

Understanding pregnant women's decision making concerning prenatal screening

OBJECTIVE: This study is aimed at enhancing understanding prenatal screening decision making through testing a hypothesized decision model based on decision theory and health behavior theory. DESIGN: We obtained questionnaires from 1,666 pregnant women who were offered prenatal screening for Down's syndrome. Path analysis (using LISREL) resulted in a final model with reasonable model fit, which was verified by split-sample cross-validation. MAIN OUTCOME MEASURES: These included perceived probability, perceived severity, attitude toward termination, response efficacy, attitude toward prenatal screening, subjective norm, child-related anxiety, and intention to undergo prenatal screening. RESULTS: Attitude toward termination of pregnancy, perceived test efficacy, and subjective norm regarding the desirability of having prenatal screening determined a woman's attitude toward having a prenatal test. Anxiety was influenced by perceived risk and perceived severity of having a child with Down's syndrome, and by subjective norm, but this appeared to be a weak predictor of intention to test. Pregnant women with a positive attitude toward prenatal screening, and who perceived a subjective norm in favor of undergoing prenatal screening, showed a greater intention to have prenatal screening done. CONCLUSION: These findings suggest that more attention should be paid toward the values and social context of pregnant women during the counseling process.     

Joint Physical Custody and Adolescents’ Life Satisfaction in 37 North American and European Countries

Joint physical custody, a parental care arrangement in which a child lives with each parent about equally after separation or divorce, is an increasingly common phenomenon in many Western countries. Although attention from family scholars, practitioners, and law professionals is growing, there are hardly any numbers on the prevalence of joint physical custody (JPC). Moreover, studies using large‐scale representative data on the effects of JPC for children’s well‐being are still rare. The data for this study come from Health Behaviour in School‐Aged Children (HBSC), a representative cross‐national survey of adolescents in 37 European and North American countries that was conducted in 2002, 2006, and 2010 and included information on students at the ages of 11, 13, and 15 years (N = 92,886). First, results revealed that symmetrical JPC after family dissolution is still very rare in the majority of countries (5% or less), but reaches 10–20% in some countries. Second, adolescents’ life satisfaction in nonintact families is higher in symmetric JPC arrangements than in asymmetric care arrangements. However, after controlling for children and family characteristics, the differences disappear. Thus, it is not the symmetric JPC arrangement that induces adolescents’ higher life satisfaction, but rather the children and family characteristics that are associated with the choice of such a custody arrangement by separated or divorced parents.     

The Big Five and identification–contrast processes in social comparison in adjustment to cancer treatment

The present study examined the relationship between social comparison processes and the Big Five personality factors. In a sample of 112 patients with various forms of cancer it was found that Neuroticism was associated with a tendency to focus on the negative interpretation of social comparison information that expressed itself in identification with fellow patients who were doing worse. This identification process also seemed to mediate the (negative) relationship between Neuroticism and post‐treatment feelings of mastery and uncertainty. No relationship was found between Neuroticism and the tendency to contrast one's situation against the situation of others who are doing better. Unexpectedly, Extraversion was most strongly related to a tendency to contrast one's situation against the situation of fellow patients who are doing better. Agreeableness, Conscientiousness and Intellect/Autonomy were unrelated to social comparison. The therapeutical implications of the findings for cancer patients are discussed. Copyright © 1999 John Wiley & Sons, Ltd.     

Editorial

Theoretical Medicine and Bioethics -     

Editorial

Theoretical Medicine and Bioethics -     

Short- and long-term consequences in decision-making under risk: immediate feedback about long-term prospects benefits people tending to impulsive processing

Many decisions in everyday life involve weighing up immediate and expected future outcomes that may be conflictive. Yet, it is still unclear which cognitive functions may affect decision-making in such situations. We examined 150 healthy subjects using a new decision-making task that measures people’s ability at handling short- and long-term consequences under objective risk. Two task versions were developed to investigate the effects of feedback about long-term consequences on decision-making. One version includes feedback about changes in long-term prospects while the other does not. Both groups revealed that advantageous decision-making correlated with reasoning and working-memory abilities, however, no correlations with executive functions were found. The effect of feedback on decision-making performance was moderated by impulsivity and need for cognition. Our findings contribute to recent dual-system approaches for risky decision-making by showing that individuals with predispositions towards impulsive rather than reflective information processing could profit from feedback about long-term prospects.