Estimation of the predictive power of the model in mixed‐effects meta‐regression: A simulation study

Several methods are available to estimate the total and residual amount of heterogeneity in meta‐analysis, leading to different alternatives when estimating the predictive power in mixed‐effects meta‐regression models using the formula proposed by Raudenbush (1994, 2009). In this paper, a simulation study was conducted to compare the performance of seven estimators of these parameters under various realistic scenarios in psychology and related fields. Our results suggest that the number of studies (k) exerts the most important influence on the accuracy of the results, and that precise estimates of the heterogeneity variances and the model predictive power can only be expected with at least 20 and 40 studies, respectively. Increases in the average within‐study sample size () also improved the results for all estimators. Some differences among the accuracy of the estimators were observed, especially under adverse (small k and ) conditions, while the results for the different methods tended to convergence for more optimal scenarios.     

Low working memory capacity is only spuriously related to poor reading comprehension

Accounts of comprehension failure, whether in the case of readers with poor skill or when syntactic complexity is high, have overwhelmingly implicated working memory capacity as the key causal factor. However, extant research suggests that this position is not well supported by evidence on the span of active memory during online sentence processing, nor is it well motivated by models that make explicit claims about the memory mechanisms that support language processing. The current study suggests that sensitivity to interference from similar items in memory may provide a better explanation of comprehension failure. Through administration of a comprehensive skill battery, we found that the previously observed association of working memory with comprehension is likely due to the collinearity of working memory with many other reading-related skills, especially IQ. In analyses which removed variance shared with IQ, we found that receptive vocabulary knowledge was the only significant predictor of comprehension performance in our task out of a battery of 24 skill measures. In addition, receptive vocabulary and non-verbal memory for serial order—but not simple verbal memory or working memory—were the only predictors of reading times in the region where interference had its primary affect. We interpret these results in light of a model that emphasizes retrieval interference and the quality of lexical representations as key determinants of successful comprehension.     

Religious Bias Among Religiously Conscious Black Christians in the United States

Research with White participants has demonstrated religious intergroup bias; however, religious identity may be different for Black Americans. Only religiously conscious Black Christians demonstrated a preference for Christian targets over Muslim and Atheist targets. Future research should consider what factors result in a person becoming conscious of other's religion.     

School System Evaluation by Value Added Analysis Under Endogeneity

Value added is a common tool in educational research on effectiveness. It is often modeled as a (prediction of a) random effect in a specific hierarchical linear model. This paper shows that this modeling strategy is not valid when endogeneity is present. Endogeneity stems, for instance, from a correlation between the random effect in the hierarchical model and some of its covariates. This paper shows that this phenomenon is far from exceptional and can even be a generic problem when the covariates contain the prior score attainments, a typical situation in value added modeling. Starting from a general, model-free definition of value added, the paper derives an explicit expression of the value added in an endogeneous hierarchical linear Gaussian model. Inference on value added is proposed using an instrumental variable approach. The impact of endogeneity on the value added and the estimated value added is calculated accurately. This is also illustrated on a large data set of individual scores of about 200,000 students in Chile.     

Hierarchical Approximate Bayesian Computation

Approximate Bayesian computation (ABC) is a powerful technique for estimating the posterior distribution of a model’s parameters. It is especially important when the model to be fit has no explicit likelihood function, which happens for computational (or simulation-based) models such as those that are popular in cognitive neuroscience and other areas in psychology. However, ABC is usually applied only to models with few parameters. Extending ABC to hierarchical models has been difficult because high-dimensional hierarchical models add computational complexity that conventional ABC cannot accommodate. In this paper, we summarize some current approaches for performing hierarchical ABC and introduce a new algorithm called Gibbs ABC. This new algorithm incorporates well-known Bayesian techniques to improve the accuracy and efficiency of the ABC approach for estimation of hierarchical models. We then use the Gibbs ABC algorithm to estimate the parameters of two models of signal detection, one with and one without a tractable likelihood function.     

From Van Gogh to Lady Gaga: Artist eccentricity increases perceived artistic skill and art appreciation

We examined the impact of eccentricity on the evaluation of artistic skills and the quality of artworks. Based on the notion that artists are typically perceived as eccentric, creative and skilled, we tested the hypothesis that eccentricity increases perceptions of artistic quality. In Study 1, Van Gogh's Sunflowers painting was evaluated more positively when he was said to have cut off his left ear lobe than when this information was not presented. In Study 2, participants liked art more when the artist was eccentric. In Study 3, the evaluation of fictitious art increased because of the artist's eccentric appearance. Study 4 established that the eccentricity effect was specific to unconventional as opposed to conventional art. In Study 5, Lady Gaga's music was more appreciated when she was displayed as highly eccentric; however, the eccentricity effect emerged only when the display seemed authentic. These novel findings indicate that art evaluations are partly rooted in perceptions of artists' eccentricity and evidence the importance of perceived authenticity and skills for these attributions. Copyright © 2014 John Wiley & Sons, Ltd.     

Inclusion: Conceptualization and measurement

In the present research, we introduced a conceptual framework of inclusion and subsequently used this as a starting point to develop and validate a scale to measure perceptions of inclusion. Departing from existing work on inclusion and complementing this with theoretical insights from optimal distinctiveness theory and self‐determination theory, we proposed that inclusion is a hierarchical two‐dimensional concept consisting of perceptions of belonging and authenticity. In addition, we posed that in the process of inclusion, it is the group rather than the individual that has primary agency. From this conceptualization, we developed and validated the 16‐item perceived group inclusion scale (PGIS). Data from two samples supported our proposed configuration of inclusion. In addition, the PGIS appeared to be a reliable measure of inclusion and was demonstrated to possess both nomological and predictive validity. Taken together, this research contributes to the conceptual refinement of the inclusion construct and offers researchers a reliable and valid tool to conduct future inclusion research. Copyright © 2014 John Wiley & Sons, Ltd.     

The Effect of Parents’ Literacy Skills and Children’s Preliteracy Skills on the Risk of Dyslexia

The combination of investigating child and family characteristics sheds light on the constellation of risk factors that can ultimately lead to dyslexia. This family-risk study examines plausible preschool risk factors and their specificity. Participants (N?=?196, 42 % girls) included familial risk (FR) children with and without dyslexia in Grade 3 and controls. First, we found impairments in phonological awareness, rapid naming, and letter knowledge in FR kindergartners with later dyslexia, and mild phonological-awareness deficits in FR kindergartners without subsequent dyslexia. These skills were better predictors of reading than arithmetic, except for rapid naming. Second, the literacy environment at home was comparable among groups. Third, having a dyslexic parent and literacy abilities of the non-dyslexic parent related to offspring risk of dyslexia. Parental literacy abilities might be viewed as indicators of offspring’s liability for literacy difficulties, since parents provide offspring with genetic and environmental endowment. We propose an intergenerational multiple deficit model in which both parents confer cognitive risks.     

The Secrecy Heuristic: Inferring Quality from Secrecy in Foreign Policy Contexts

Three experiments demonstrate that in the context of U.S. foreign policy decision making, people infer informational quality from secrecy. In Experiment 1, people weighed secret information more heavily than public information when making recommendations about foreign political candidates. In Experiment 2, people judged information presented in documents ostensibly produced by the Department of State and the National Security Council as being of relatively higher quality when those documents were secret rather than public. Finally, in Experiment 3, people judged a National Security Council document as being of higher quality when presented as a secret document rather than a public document and evaluated others' decisions more favorably when those decisions were based on secret information. Discussion centers on the mediators, moderators, and broader implications of this secrecy heuristic in foreign policy contexts.