Bayesian inference for psychology. Part II: Example applications with JASP

Bayesian hypothesis testing presents an attractive alternative to p value hypothesis testing. Part I of this series outlined several advantages of Bayesian hypothesis testing, including the ability to quantify evidence and the ability to monitor and update this evidence as data come in, without the need to know the intention with which the data were collected. Despite these and other practical advantages, Bayesian hypothesis tests are still reported relatively rarely. An important impediment to the widespread adoption of Bayesian tests is arguably the lack of user-friendly software for the run-of-the-mill statistical problems that confront psychologists for the analysis of almost every experiment: the t-test, ANOVA, correlation, regression, and contingency tables. In Part II of this series we introduce JASP (http://www.jasp-stats.org), an open-source, cross-platform, user-friendly graphical software package that allows users to carry out Bayesian hypothesis tests for standard statistical problems. JASP is based in part on the Bayesian analyses implemented in Morey and Rouder’s BayesFactor package for R. Armed with JASP, the practical advantages of Bayesian hypothesis testing are only a mouse click away.     

Reliability and construct validity of the Dutch psychopathy checklist: youth version: findings from a sample of male adolescents in a juvenile justice treatment institution

The present study examines the reliability and construct validity of the Dutch version of the Psychopathy Check List: Youth Version (PCL:YV) in a sample of male adolescents admitted to a secure juvenile justice treatment institution (N = 98). Hare's four-factor model is used to examine reliability and validity of the separate dimensions of psychopathy. Interrater reliabilities are good to excellent for the PCL:YV total score and most factor scores, except for the affective factor. Several suggestions are offered for optimizing reliability of this factor. Finally, meaningful associations between PCL:YV scores and scores on the Minnesota Multiphasic Personality Inventory-Adolescent and the Interpersonal Checklist-Revised support the construct validity of the PCL:YV total score as well as the four factors in the Dutch context.     

Early maternal deprivation retards neurodevelopment in Wistar rats

A single 24 h period of maternal deprivation (MD) in rats has been shown to induce, in adulthood, a number of abnormalities in brain and behaviour that also occur in patients with schizophrenia. However, the short-term behavioural effects of MD have not been studied in detail. Since patients with schizophrenia are characterized by a retardation of normal development, we aimed in the present study to investigate the development of control rats and rats that were exposed to MD on postnatal day 9. Compared to control animals, MD rats showed (1) a reduction in body weight, (2) an increased in reversal latency in negative geotaxis, (3) a delayed eye opening, (4) a delayed emergence of walking and rearing; and (5) a delayed emergence of the behavioural response to amphetamine (amph). On the other hand, MD and control rats responded similarly to the non-competitive NMDA antagonist MK801. These data clearly show that early MD delays development, especially of the dopaminergic system and confirm our hypothesis that MD may represent an interesting animal model for the neurodevelopmental hypothesis of schizophrenia.     

Distancing from a stigmatized social identity: State of the art and future research agenda on self-group distancing

Despite equal rights, minority groups such as ethnic minorities, LGBTQ + people, and people with mental or physical disabilities face discrimination on a day-to-day basis in subtle and hard-to-recognize forms. As discrimination slips beneath the surface, it becomes difficult to fight the stigma using collective social identity coping mechanisms. Instead, individual mobility responses such as distancing the self from the stigmatized identity (“self-group distancing”) become more viable as a way to improve one's individual standing. In this overview of the state of the art, we take a social identity lens to reflect on the current empirical knowledge base on self-group distancing as a coping mechanism and provide a framework on what self-group distancing is; when, where and why self-group distancing likely occurs; and what its consequences are at the individual and the collective level. The contributions in this special issue provide novel insights into how these processes unfold, and serve as a basis to set a future research agenda, for example on what can be done to prevent self-group distancing (i.e., interventions). Together, the insights highlight that while self-group distancing may seem effective to (strategically and temporarily) alleviate discomfort or to improve one's own position, on a broader collective level and over time self-group distancing tends to keep the current unequal social hierarchy in place.     

Under the Spell of the Ring

Among orthodox reformed Christians in the Netherlands fierce debates have occurred on moral aspects of Christian life. This essay discusses three major controversial moral issues that are related to conceptions of sex, gender, and sexuality: divorce/remarriage, women’s ordination, and homosexuality. By analysing several contributions to debates on these issues, it proposes and explores a hypothesis that concerns the role of a particular understanding of marriage as characterized by a hermeneutical construct: a communal, deeply rooted and subconscious normative principle that drives our interpretations of texts and practices. This essay illustrates the problems of both the dominance of marriage within Christian communities and lived faith, as well as the modern, romantic aspects of this particular understanding of marriage.     

Fragility of Happiness Beliefs Across 15 National Groups

The belief that happiness is fragile—that it is fleeting and may easily turn into less favourable states—is common across individuals and cultures. However, not much is known about this belief domain and its structure and correlates. In the present study, we use multigroup confirmatory factor analysis and multilevel modelling to investigate the measurement invariance, cross-level isomorphism, predictive validity, and nomological network of the fragility of happiness scale across 15 nations. The results show that this scale has good statistical properties at both individual and cultural levels, and is associated with relevant psycho-social concepts in expected directions. The importance of the results, limitations, and potential directions for future research are discussed.