Meta‐CART: A tool to identify interactions between moderators in meta‐analysis

In the framework of meta‐analysis, moderator analysis is usually performed only univariately. When several study characteristics are available that may account for treatment effect, standard meta‐regression has difficulties in identifying interactions between them. To overcome this problem, meta‐CART has been proposed: an approach that applies classification and regression trees (CART) to identify interactions, and then subgroup meta‐analysis to test the significance of moderator effects. The previous version of meta‐CART has its shortcomings: when applying CART, the sample sizes of studies are not taken into account, and the effect sizes are dichotomized around the median value. Therefore, this article proposes new meta‐CART extensions, weighting study effect sizes by their accuracy, and using a regression tree to avoid dichotomization. In addition, new pruning rules are proposed. The performance of all versions of meta‐CART was evaluated via a Monte Carlo simulation study. The simulation results revealed that meta‐regression trees with random‐effects weights and a 0.5‐standard‐error pruning rule perform best. The required sample size for meta‐CART to achieve satisfactory performance depends on the number of study characteristics, the magnitude of the interactions, and the residual heterogeneity.     

The prevalence of false confessions in experimental laboratory simulations: A meta‐analysis

We assessed experimental false confession studies using a meta‐analysis to evaluate the prevalence of false confessions across methodologies and several moderator variables. False confessions were more likely in typing task studies than in collaborative or individual cheating studies. In typing studies, speed of typing did not affect false confession rates, but placement of the forbidden key in locations that rendered errors less plausible lowered the false confession rates. False‐evidence ploys increased the likelihood of false confessions. We explore implications for courts, expert witnesses, scholars, and police interrogators.     

The relative impact of workplace bullying as a social stressor at work

Hauge, L. J., Skogstad, A. & Einarsen, S. (2010). The relative impact of workplace bullying as a social stressor at work. Scandinavian Journal of Psychology, 51, 426–433. Exposure to workplace bullying has been argued to be a severe social stressor and a more crippling and devastating problem for affected individuals than the effects of all other work‐related stressors put together. However, few studies have explicitly investigated this assumption. In a representative sample of the Norwegian working population, the present study investigated the relative contribution of workplace bullying as a predictor of individual and organizational related outcomes after controlling for the well‐documented job stressors of job demands, decision authority, role ambiguity and role conflict. Bullying was found to be a significant predictor of all the outcomes included, showing a substantial relative contribution in relation to anxiety and depression, while for job satisfaction, turnover intention and absenteeism, more modest relative contributions were identified. Workplace bullying is indeed a potent social stressor with consequences similar to, or even more severe than, the effects of other stressors frequently encountered within organizations. Thus, the finding that bullying has a considerable effect on exposed individuals also when controlling for the effects of other job stressors demonstrates bullying as a serious problem at workplaces that needs to be actively prevented and managed in its own right.     

Vertical vs horizontal bullying: A need of socio‐interactive ethical trainings at workplace

Bullying at workplaces is a growing problem associated with several antecedents and outcomes of psychological disorders. Extant literature shows the relationship of victimization with the owning‐up curriculum to confront bullying, but so far there is little research to cure the issue of bullying through ethics and there is no study to check the impact of ethical lessons and exercises in training materials to curb bullying at workplace. The current paper is based on a literature review of aggression and bullying, and chiefly addresses the HR practices in rescuing the people from peer victimization. Conceptually segregating supervisor‐subordinate (vertical) and peer‐peer (horizontal) bullying psychology, this paper attempts to see what possible corrective steps can be taken by senior managers, supervisors and psychologists to resolve this critical problem through interior capacities. In this paper, we have developed three propositions for conducting a future empirical investigation in connection to a cohort study. By addressing the counterproductive/deviant behavior, the present report is likely to be beneficial for psychology scientists and HR practitioners in noticing and resolving the bullying issues at the workplace for the well‐being of employees.     

The prospective relationship between role stressors and new cases of self‐reported workplace bullying

In line with the “Work environment hypothesis,” role stressors have been proposed as important antecedents of bullying in the workplace. Only a few longitudinal studies on the relationship between role stressors and bullying exist, however, and earlier studies have largely been cross‐sectional. The aim of the present prospective study was to determine whether role stressors at baseline predict new cases of workplace bullying at follow‐up. A total of 2,835 Norwegian employees participated at both baseline and follow‐up, with an interval of two years between the measurements. The study supports the hypotheses that role ambiguity and role conflict, independently, contribute to subsequent new reports of workplace bullying. However, there was a weak reverse effect: reporting being bullied at work at baseline predicted reporting increased levels of role ambiguity and role conflict at follow‐up. Even though the results may indicate a circular relationship between the variables at hand, the weak reverse relationship seems to have little practical impact compared to the stronger relationship from role stressors to bullying. Hence, the results mainly support the hypotheses stating that role ambiguity and role conflict, independently, predict subsequent exposure to workplace bullying.     

20 Years of workplace bullying research: A review of the antecedents and consequences of bullying in the workplace

Research on workplace bullying, which has just recently passed the 20 year mark, has grown significantly over this duration of time. We provide an extensive review of the extant literature, with a focus on the antecedents and consequences of workplace bullying. We organize our review of the extant literature by level of analysis, which allows us to understand workplace bullying from each major level of analysis, while simultaneously identifying those levels at which research has been sparse. We then develop a conceptual model based on our review that similarly depicts theoretical and/or empirical findings from the extant literature, but in a succinct manner. Based on our review and conceptual model, we identify and highlight a number of key avenues for future research that will help extend the current workplace bullying literature.     

The meta‐analysis of partial effect sizes

This paper discusses the synthesis of partial effect sizes derived from multivariate settings. The general statistical properties of the d‐effect size are derived, extending Hedges's statement of zero‐order properties. These general properties have direct relevance in the synthesis of a set of independent effect sizes arising from empirical studies predicated on a common theoretical model. We discuss possible solutions to the problem of comparing effect sizes arising from models employing differing sets of covariates. We apply the general statistical properties in the synthesis of gender performance differences in first‐level economics courses at three New Zealand universities. The model of academic performance is based on Spearman's conception of general academic ability and specific ability in economics.     

The prevalence,risk factors and outcomes of workplace bullying among junior doctors: a systematic review

ABSTRACT

Junior doctors’ exposure to bullying may impact their training and compromise quality healthcare, yet little is known in relation to its predictors and effects. The aim of this paper is to assess the prevalence, factors and outcomes of workplace bullying among junior doctors. Literature search was performed to identify all primary studies examining workplace bullying among junior doctors using the following electronic databases: Medline, Scopus, Web of Science, PsycINFO and Cochrane Library. A total of 18 articles were included, reporting on a total of 9,597 junior doctors. The quality of evidence can be rated as moderate according to the Newcastle Ottawa Scale. From the review, a wide range (30–95%) of bullying prevalence, significant differences in bullying rates according to gender, age, height, ethnicity and subspecialty, and significant associations between bullying and mental strain, job dissatisfaction, burnout, and increased accidents at work were observed. Concurrently, heterogeneity in the terms and methodologies used to examine workplace bullying as well as definitional issues in relation to the persistency of negative interactions were noted. Evidence suggests that workplace bullying is a serious occupational hazard for junior doctors, and more research is warranted to better understand this phenomenon and address its definitional and methodological issues.     

Workers' perception of workplace bullying: A cross-cultural study

This study is one of the first studies to approach workplace bullying cross-culturally. It sought to compare employees' understanding of workplace bullying in two different world regions: Central America and Southern Europe, regarding three aspects of workplace bullying: psychological vs. physical harassment, hierarchical vs. horizontal bullying, and direct vs. indirect aggression. A convenience sample of 246 workers provided their own definition of workplace bullying through a single, open-ended question. The results showed that employees from Central America emphasized the physical component of workplace bullying more than the Southern European employees. However, similarities in the conceptualization of workplace bullying across both cultures were found as well. Both Southern European and Central American employees defined workplace bullying mainly as a hierarchical phenomenon, where the aggression took the form of direct strategies. Such differences and similarities bring to the field some positive inputs for the development and implementation of different strategies for dealing effectively with this phenomenon.     

Analysis of categorical moderators in mixed‐effects meta‐analysis: Consequences of using pooled versus separate estimates of the residual between‐studies variances

Subgroup analyses allow us to examine the influence of a categorical moderator on the effect size in meta‐analysis. We conducted a simulation study using a dichotomous moderator, and compared the impact of pooled versus separate estimates of the residual between‐studies variance on the statistical performance of the Q _{B (P)} and Q _{B (S)} tests for subgroup analyses assuming a mixed‐effects model. Our results suggested that similar performance can be expected as long as there are at least 20 studies and these are approximately balanced across categories. Conversely, when subgroups were unbalanced, the practical consequences of having heterogeneous residual between‐studies variances were more evident, with both tests leading to the wrong statistical conclusion more often than in the conditions with balanced subgroups. A pooled estimate should be preferred for most scenarios, unless the residual between‐studies variances are clearly different and there are enough studies in each category to obtain precise separate estimates.     

The reliability of romantic love: A reliability generalization meta‐analysis

The present study is a reliability‐generalization meta‐analysis of 5 commonly used measures of romantic love: Rubin’s Loving and Liking scales, the Love Attitudes Scale, the Love Attitudes Scale–Short Form, the Passionate Love Scale, and the Triangular Love Scale. Data from 127 studies representing 38,132 participants provided internal consistency reliability estimates. The studies provide information on the average score reliability across studies and the effect of sample characteristics on score reliability across measures. The reliability of scores from several measures proved to be susceptible to the influence of sample characteristics, most notably, the ethnicity of the sample. The discussion provides recommendations to researchers and focuses on the ramifications of score reliability on love research.     

A meta‐analysis of psychopathy‐, antisocial PD‐ and FFM associations

This research meta‐analytically summarizes the relationships of the Five‐Factor Model (FFM) with psychopathy and Antisocial Personality Disorder (APD). Effect sizes of the associations between psychopathy, APD and the FFM were compiled from 26 independent samples (N = 6913) for psychopathy and 57 independent samples (N = 16 424) for APD. The results revealed predominantly points of similarity and some differences in the FFM associations of both disorders. Symptoms of psychopathy and APD were negatively associated with Conscientiousness and Agreeableness facets and positively with scores on Angry–Hostility (N2), Impulsiveness (N5), Excitement Seeking (E5) and negatively with Warmth (E1). Only psychopathy had a small negative association with Anxiety (N1) and was characterized by stronger negative associations with Agreeableness and Straightforwardness (A2), Compliance (A4) and Modesty (A5) compared to APD. The moderator analyses showed that sample type, use of the NEO‐PI‐R and APD instrument moderated the APD FFM associations, while psychopathy instrument and age group were moderators in the psychopathy MA. Implications of this research for the assessment of APD and psychopathy relying on dimensional models of personality pathology are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Self‐control depletion impairs goal maintenance: A meta‐analysis

Initial exertion of self‐control has been suggested to impair subsequent self‐regulatory performance. The specific cognitive processes that underlie this ego depletion effect have rarely been examined. Drawing on the dual‐process theory of executive control (Engle & Kane, 2004 ; Kane & Engle, 2003 ), the current meta‐analysis revealed that initial self‐control exertion impairs participants’ capacities of maintaining the task goal but its effect on capacities of resolving response competition is in need of further investigation. Our results are more consistent with recent theoretical views that consider ego depletion as a switch cost and a result arising from reduced motivation to engage in further self‐control.