Heterogeneous heterogeneity by default: Testing categorical moderators in mixed-effects meta-analysis

Categorical moderators are often included in mixed-effects meta-analysis to explain heterogeneity in effect sizes. An assumption in tests of categorical moderator effects is that of a constant between-study variance across all levels of the moderator. Although it rarely receives serious thought, there can be statistical ramifications to upholding this assumption. We propose that researchers should instead default to assuming unequal between-study variances when analysing categorical moderators. To achieve this, we suggest using a mixed-effects location-scale model (MELSM) to allow group-specific estimates for the between-study variance. In two extensive simulation studies, we show that in terms of Type I error and statistical power, little is lost by using the MELSM for moderator tests, but there can be serious costs when an equal variance mixed-effects model (MEM) is used. Most notably, in scenarios with balanced sample sizes or equal between-study variance, the Type I error and power rates are nearly identical between the MEM and the MELSM. On the other hand, with imbalanced sample sizes and unequal variances, the Type I error rate under the MEM can be grossly inflated or overly conservative, whereas the MELSM does comparatively well in controlling the Type I error across the majority of cases. A notable exception where the MELSM did not clearly outperform the MEM was in the case of few studies (e.g., 5). With respect to power, the MELSM had similar or higher power than the MEM in conditions where the latter produced non-inflated Type 1 error rates. Together, our results support the idea that assuming unequal between-study variances is preferred as a default strategy when testing categorical moderators.     

A meta-analytic evaluation of diversity training outcomes across cultures

The extant literature on diversity training suggests that its effect size is small and varies across studies, calling for theorization on when and why diversity training does or does not work. In this article, we propose that the national cultural context is a critical moderator and conduct a meta-analysis to examine its influence on diversity training. Our analyses show that the average effect size of diversity training outcomes is significant both inside and outside the U.S. The effect size of specific diversity training design is contingent on such cultural values as power distance, individualism, masculinity, and uncertainty avoidance. We conclude our review by providing future directions for cross-cultural research on diversity training.     

A general linear model for estimating effect size in the presence of publication bias

When the process of publication favors studies with smallp-values, and hence large effect estimates, combined estimates from many studies may be biased. This paper describes a model for estimation of effect size when there is selection based on one-tailedp-values. The model employs the method of maximum likelihood in the context of a mixed (fixed and random) effects general linear model for effect sizes. It offers a test for the presence of publication bias, and corrected estimates of the parameters of the linear model for effect magnitude. The model is illustrated using a well-known data set on the benefits of psychotherapy.Authors' note: The contributions of the authors are considered equal, and the order of authorship was chosen to be reverse-alphabetical.     

社交媒体使用与错失焦虑的关系：一项元分析

社交媒体使用与错失焦虑均是当下生活中较为常见的现象, 诸多研究探讨了两者间的内在联系, 但研究结果却存在很大差异。为明确两者之间的整体关系, 以及产生分歧的原因, 对检索后获得的65项研究(70个独立样本)使用随机效应模型进行了元分析。结果发现：社交媒体使用与错失焦虑存在显著正相关(r = 0.38, 95% CI [0.34, 0.41]); 二者的相关强度受社交媒体使用测量指标和社交媒体类型的调节, 但不受性别、年龄、错失焦虑测量工具和个体主义指数的调节。结果一定程度上澄清了大众传播的社会认知理论和数字恰到好处假说的争论, 表明社交媒体使用程度越高的人往往也会伴随着较高水平的错失焦虑。防止社交媒体过度使用, 尤其是引导大众合理使用以图像为中心并且开放度较高的社交媒体有助于错失焦虑的缓解。     

2004至2016年中国大学生身体自尊的变迁:一项横断历史研究

大学生身体自尊是如何随年代变化的呢？研究对2004年至2016年107篇使用身体自尊量表的研究进行了横断历史研究,涉及大学生30738名。结果显示：（1）我国大学生身体自我价值感、运动能力和身体素质与年代有着显著正相关关系;（2）男女大学生身体自尊水平都有了一定提升;（3）男生在身体自尊各个因子的得分高于女生0.2~0.3个标准差,显示出了大学生在身体自尊水平上的性别差异;（4）从大学生整个群体来看,经济因素、高等教育因素与大学生身体自尊具有显著相关,而从不同性别群体来看,经济因素与人口压力对于男大学生的身体自尊影响更为明显。     

高自尊易宽恕?基于中国青少年样本的研究

目的:以中国青少年为被试样本,整合已有自尊与宽恕关系的研究,运用元分析技术,明晰二者之间的整体关系,分析以往研究结论产生分歧的原因。方法:采用中国知网、万方数据库、Web of Science等检索系统搜索自尊与宽恕的相关文献,遴选出符合元分析研究标准的有效文献31项,70个独立样本,共计被试31516名。结果:(1)自尊与宽恕间存在中度相关,自尊可正向预测宽恕,验证了高自尊者易宽恕。(2)自我宽恕比人际宽恕与自尊的关系更为密切。(3)宽恕测量工具、被试类别、宽恕结构对自尊与宽恕的关系调节作用明显,性别无显著调节效应。     

老年人心理韧性与幸福感的关系:一项元分析

采用元分析方法探讨老年人心理韧性和幸福感之间的关系, 通过文献检索和筛选, 共有42篇中英文文献, 75个独立样本纳入元分析(N = 12856)。结果显示, 老年人心理韧性和幸福感、生活满意度、积极情感呈显著正相关关系, 与消极情感之间呈显著负相关关系; 两者之间的关系受心理韧性的测量工具、文化背景、文献质量、文献年份、样本量和样本人群年龄的影响。研究结果为心理韧性如何影响老年人幸福感提供了较为精确的估计, 对于提高老年人幸福感进而实现成功老化具有重要意义。     

自恋与行为抑制/激活系统的关系：元分析

运用元分析方法探讨自恋与行为抑制/激活系统的关系。经过文献检索和筛选, 纳入原始文献19篇, 包含25个独立样本, 共7702名被试。根据同质性检验结果, 选用随机效应模型。结果发现, 自恋与行为抑制系统存在中度负相关(r = -0.27, 95% CI为[-0.34, -0.21]), 自恋测量工具在两者间起显著的调节作用; 自恋与行为激活系统存在高度正相关(r = 0.46, 95% CI为[0.40, 0.52]), 被试类型在两者间起显著的调节作用。自恋与行为抑制/激活系统的密切关系支持了自恋的主体性理论和人格强化敏感性理论。     

反刍思维与社交焦虑的关系:来自元分析的证据

反刍思维与社交焦虑的关系一直存在争议,为探究这些研究结论不一致的原因,本研究采用元分析技术研究反刍思维与社交焦虑的关系.综合国内国外研究42篇,中文文献8篇,英文文献34篇,共53个独立样本,总样本23032人.研究结果显示,反刍思维与社交焦虑呈高度正相关(r=0.42),反刍思维与社交焦虑的关系受到年龄段、反刍思维使...