Robust regression: Testing global hypotheses about the slopes when there is multicollinearity or heteroscedasticity

A well-known concern regarding the usual linear regression model is multicollinearity. As the strength of the association among the independent variables increases, the squared standard error of regression estimators tends to increase, which can seriously impact power. This paper examines heteroscedastic methods for dealing with this issue when testing the hypothesis that all of the slope parameters are equal to zero via a robust ridge estimator that guards against outliers among the dependent variable. Included are results related to leverage points, meaning outliers among the independent variables. In various situations, the proposed method increases power substantially.     

Youth Risk and Mentoring Relationship Quality: The Moderating Effect of Program Experiences

Because program experiences are more amendable than mentor or mentee characteristics, they may be important factors to consider in buffering the negative impact of youth risk on the quality of the mentor–mentee bond. Data from 455 mentees (ages 11–18; 57% male) and their undergraduate student mentors (82.3% female) from the Campus Connections mentoring program were used to assess whether youth risk and mentors’ program experiences (i.e., program structure, supportive relationships with staff, opportunities for skill building, support for efficacy and mattering, and opportunities to belong) were associated with mentoring relationship quality and whether mentors’ experience within the program moderated the association between youth risk and mentoring relationship quality. Results indicated that environmental, but not individual, risk was negatively associated with relationship quality. Mentors’ experiences with the program were positively associated with mentoring relationship quality, and in many cases, above and beyond youth level of risk. Finally, mentors’ perception of program structure, supportive relationships, and opportunities for skill building attenuated the negative relationship between environmental, but not individual, risk and relationship quality. Mentors’ experiences of program support for efficacy and mattering and opportunities to belong were not significant moderators in any model. Implications for programs and future research directions are presented.     

Promoting positive community relations: what can RE learn from social psychology and the shared space project?

In this article we considered the relevance of specific claims that ‘multi-faith’ approaches to Religious Education (RE) play a role in promoting good community relations. In doing so, we adopted a social-psychological perspective where engaging in positive and meaningful interactions with diverse others reduces prejudice. Survey responses from 92 RE teachers across the UK were examined to determine the extent to which strategies for promoting positive community relations were embedded within classroom practice. We next examined whether teachers intuitively used social psychological theory – namely the contact hypothesis – to promote positive communities in their classrooms. Results demonstrated that the majority of surveyed RE practitioners perceived community relations to be a core aim of RE and that contact theory was applicable to their practice. Teachers reported examples of how they embed both contact theory and RE in their classrooms but not all of these aligned with social psychological theory. Findings suggest that successful practice in RE may be further developed by integrating theoretical principles of the contact hypothesis. Implications and future directions will be discussed.     

Social cognition after head injury: sarcasm and theory of mind

Closed head injury (CHI) is associated with communication difficulties in everyday social interactions. Previous work has reported impaired comprehension of sarcasm, using sarcastic remarks where the intended meaning is the opposite of the sincere or literal meaning. Participants with CHI in the present study were assessed using two types of sarcastic items, those with a directly opposite meaning and those with an indirect, non-literal but not directly opposite meaning. The CHI group was differentially poorer at comprehending sarcastic versus sincere remarks, although type of sarcastic materials did not influence performance. Errors involved not only literal interpretations, but also incorrect non-literal interpretations. Theory of mind (mentalising) was also assessed by comparing comprehension of human actions with control physical events. The CHI group was selectively impaired on the mentalising component of this task, and mentalising scores correlated with sarcasm comprehension. The implications of the findings for our understanding of impaired sarcastic comprehension after acquired brain injury are discussed.     

Culture and social support: who seeks it and why?

Are Asians and Asian Americans more or less likely to seek social support for dealing with stress than European Americans? On the one hand, the collectivist orientation of Asian countries might favor the sharing of stressful problems; on the other hand, efforts to maintain group harmony might discourage such efforts. In 2 studies, Koreans (Study 1) and Asians and Asian Americans in the United States (Study 2) reported using social support less for coping with stress than European Americans. Study 3 examined potential explanations for these effects and revealed that relationship concerns accounted for the cultural differences in use of support seeking. Discussion centers on the potential benefits and liabilities of seeking social support.     

Brain activation during semantic processing in autism spectrum disorders via functional magnetic resonance imaging

Language and communication deficits are core features of autism spectrum disorders (ASD), even in high-functioning adults with ASD. This study investigated brain activation patterns using functional magnetic resonance imaging in right-handed adult males with ASD and a control group, matched on age, handedness, and verbal IQ. Semantic processing in the controls produced robust activation in Broca's area (left inferior frontal gyrus) and in superior medial frontal gyrus and right cerebellum. The ASD group had substantially reduced Broca's activation, but increased left temporal (Wernicke's) activation. Furthermore, the ASD group showed diminished activation differences between concrete and abstract words, consistent with behavioral studies. The current study suggests Broca's area is a region of abnormal neurodevelopment in ASD, which may be linked with semantic and related language deficits frequently observed in ASD.     

Neutralizing substitutes for leadership theory: leadership effects and common-source bias

The purpose of this research was to examine alternative models of substitutes for leadership theory given the general lack of empirical support for the moderating effects postulated by the theory. On this basis, the research posited that the effects of substitutes also could be conceptualized as mediated relations. The research examined moderated and mediated relations for several sets of leader behaviors and substitutes that have been examined in the literature. The research design sampled 49 organizations, with 940 subordinates rating 156 leaders. Results, although generally not supportive of the moderator or mediator hypotheses, essentially demonstrated that leadership matters. The findings also suggest that prior significant effects in substitutes literature may be merely a statistical artifact, resulting from common-source bias.     

Two tests of the stuck-in-time hypothesis

The authors report 2 experiments that test the stuck-in-time hypothesis, which argues that animals cannot time-date events and thus do not remember when events occurred and do not anticipate future events. In Experiment 1, rats in the experimental condition could earn a large reward by reentering the 1st arm that they visited on a radial maze. They did not learn to reenter this arm early and did no better than did a control group that was not given a large reward for reentering the first arm. In Experiment 2, rats in the experimental group could earn a large reward by delaying entry into a distinctive arm. These rats did not learn to delay entry into the distinctive arm, and they performed no better than did the control-group rats, which did not receive a large reward for delayed entry. These experiments provide further evidence in support of the stuck-in-time hypothesis.