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.     

Bayesian inference for psychology. Part I: Theoretical advantages and practical ramifications

Bayesian parameter estimation and Bayesian hypothesis testing present attractive alternatives to classical inference using confidence intervals and p values. In part I of this series we outline ten prominent advantages of the Bayesian approach. Many of these advantages translate to concrete opportunities for pragmatic researchers. For instance, Bayesian hypothesis testing allows researchers to quantify evidence and monitor its progression as data come in, without needing to know the intention with which the data were collected. We end by countering several objections to Bayesian hypothesis testing. Part II of this series discusses JASP, a free and open source software program that makes it easy to conduct Bayesian estimation and testing for a range of popular statistical scenarios (Wagenmakers et al. this issue).     

Estimating psychological networks and their accuracy: A tutorial paper

The usage of psychological networks that conceptualize behavior as a complex interplay of psychological and other components has gained increasing popularity in various research fields. While prior publications have tackled the topics of estimating and interpreting such networks, little work has been conducted to check how accurate (i.e., prone to sampling variation) networks are estimated, and how stable (i.e., interpretation remains similar with less observations) inferences from the network structure (such as centrality indices) are. In this tutorial paper, we aim to introduce the reader to this field and tackle the problem of accuracy under sampling variation. We first introduce the current state-of-the-art of network estimation. Second, we provide a rationale why researchers should investigate the accuracy of psychological networks. Third, we describe how bootstrap routines can be used to (A) assess the accuracy of estimated network connections, (B) investigate the stability of centrality indices, and (C) test whether network connections and centrality estimates for different variables differ from each other. We introduce two novel statistical methods: for (B) the correlation stability coefficient, and for (C) the bootstrapped difference test for edge-weights and centrality indices. We conducted and present simulation studies to assess the performance of both methods. Finally, we developed the free R-package bootnet that allows for estimating psychological networks in a generalized framework in addition to the proposed bootstrap methods. We showcase bootnet in a tutorial, accompanied by R syntax, in which we analyze a dataset of 359 women with posttraumatic stress disorder available online.     

Mental contents in transfer

The purpose of this paper is to develop theoretical concepts for mental content-based investigations and explanations in the psychology of human thinking in general and transfer more specifically. The schema-based analysis of transfer postulates that the solving of an earlier problem can influence a person's future behavior only to the degree of schematic similarity between the primary and the secondary problem solution. The reported content-based investigation, using Duncker's (1935) classic tumor task, shows however, that the contents of schemata cause an essential variation in a person's mental representation and judgement of radiation confluence effects. The study identified and assessed in separate experiments the influence of three different thought models (additive, balancing, and distribution-based) and two distinct types of spatial images of rays (compact vs. diverging). Whereas differences in the central tendencies of the judgements could expose some of the priming effects between experimental conditions, the core of the content-based analysis was based on the identification of distinct groups of participants displaying a certain type of judgement. These differences reflected the contrasts between the thought models and the ray image content. They substantiated the claim that a schema-based analysis of transfer and reasoning in general, is alone not sufficient to explain interindividual and intercontextual differences that are based on distinctive mental content in the reasoners' apperception.     

Responses to olfactory stimuli in spotted hyenas (Crocuta crocuta): I. Investigation of environmental odors and the function of rolling

Olfaction is crucial to spotted hyenas (Crocuta crocuta), yet there are no controlled studies of their reactions to odors. In Experiment 1, the authors examined responses of captive hyenas to various environmental (prey, nonprey animal, and plant) odors. Subjects approached and sniffed all odors equally but preferentially licked prey odors, scent marked next to odors, and rolled in animal-based odors. In Experiment 2, the authors examined the function of rolling by applying odors to the pelts of captive hyenas. When hyenas wore carrion, they gained positive social attention (increased investigation and allogrooming) from pen mates, but when they wore camphor, the normal social greeting ceremony was curtailed. Thus, olfactory stimuli elicit specific responses, influence where behavior is directed, and can be used to affect social interaction.     

Interventions for inappropriate sexual behavior in individuals with intellectual and developmental disabilities: A brief review

Although prevalence rates vary, 6% to 28% of individuals with intellectual or developmental disabilities (IDDs) engage in inappropriate sexual behavior (ISB), ranging from public masturbation to sexually aggressive behavior. Along with increased risk for contacting the criminal justice system, people with IDDs who display ISB may encounter negative social consequences, restricted community access and barriers to independence, and a variety of counter-therapeutic outcomes. The purpose of the present review is to highlight recent, efficacious behavior-analytic treatments for ISB in individuals with IDDs. Ethical considerations and areas for future research will be discussed.     

Validating the virtual string task with the gap test

Relational concepts—such as connectedness—may be easy for human adults to appreciate; but, obtaining evidence of other species’ understanding of connectedness has been challenging. One key test of connectedness involves an organism’s responding to variants of the string task. Using a virtual string task, we gave pigeons a pair of strings from which to choose: one connected to a full dish of food and a second disconnected from another full dish of food. Our pigeons did not at first choose the connected string under conditions of non-differential reinforcement; later, the birds rapidly learned to choose the connected string under conditions of differential reinforcement. Our results replicate prior findings with real strings and food dishes, thereby demonstrating that pigeons can appreciate the connectedness between a string tether and a dish of food, and attesting to the utility and fidelity of the virtual string task.     

Effects of treatment‐integrity failures on a response‐cost procedure

Effects of incorrect or partial implementation (poor treatment integrity) on response cost are largely unknown. We evaluated reduced treatment integrity during response cost on rates of 2 concurrently available responses. College students earned points by clicking on either a black circle or a red circle on a computer screen. Experiment 1 compared 2 types of treatment‐integrity failures (omission and commission errors) across 2 levels of integrity (20% and 50%). Compared to 100% integrity conditions, omission errors did not suppress responding to the same extent, and commission errors reduced target responding but also decreased rates of alternative behavior. Experiment 2 compared the effects of 20% and 50% omission errors within subjects. Implementation at 50% integrity adequately suppressed responding, but treatment effects were lost at 20% integrity. There may be a critical level at which response cost must be implemented to suppress responding, which has important implications for application.     

Do You Know What I Feel? Partners' Predictions and Judgments of Each Other's Emotional Reactions to Emotion-Eliciting Situations

The goal of the present study was to investigate empathic accuracy in couples, specifically the partners' ability to predict each other's emotional reactions to social situations. For this, 36 French Canadian couples aged from 18 to 34 years predicted their own reactions as well as their partner's reactions to a series of emotional situations. They then role-played these emotional situations while being videotaped. At a later time, the taped role-play segments were rated by the role-play actors themselves, by their partners, and by 5 individuals who did not know the actors. Results revealed high levels of empathic accuracy when we compared the partners' predictions of each other's reactions. However, when these predictions were compared with the participants' self-evaluations of their role-plays or with evaluations by individuals who did not know the actors, partners showed a positive bias in that they predicted more appropriate and fewer inappropriate reactions to the social situations for their partners than were self-rated by the partners themselves or rated by individuals who did not know the actors. Finally, the existence of couple-specific private meaning systems could not be confirmed in the present context as the evaluations of emotional expressions by unknown others, the actors' partners, and the actors themselves were largely congruent.