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).     

Timed picture naming in seven languages

Timed picture naming was compared in seven languages that vary along dimensions known to affect lexical access. Analyses over items focused on factors that determine cross-language universals and cross-language disparities. With regard to universals, number of alternative names had large effects on reaction time within and across languages after target-name agreement was controlled, suggesting inhibitory effects from lexical competitors. For all the languages, word frequency and goodness of depiction had large effects, but objective picture complexity did not. Effects of word structure variables (length, syllable structure, compounding, and initial frication) varied markedly over languages. Strong cross-language correlations were found in naming latencies, frequency, and length. Other-language frequency effects were observed (e.g., Chinese frequencies predicting Spanish reaction times) even after within-language effects were controlled (e.g., Spanish frequencies predicting Spanish reaction times). These surprising cross-language correlations challenge widely held assumptions about the lexical locus of length and frequency effects, suggesting instead that they may (at least in part) reflect familiarity and accessibility at a conceptual level that is shared over languages.     

Perception of the Mccolloch Effect Correlates with Activity in Extrastriate Cortex: A Functional MagneticResonance Imaging Study

The McCollough effect is a striking color aftereffect that is linked to the orientation of the patterns used to induce it. To produce the McCollough effect, two differently oriented grating patterns, such as a red-and-black vertical grating and a green-and-black horizontal grating, are viewed alternately for a few minutes. After such colored gratings are viewed, the white sections of avertical black-and-white test grating appear to be tinged with green, and the white sections of a horizontal grating appear to be tinged with pink. We present evidence from a functional magnetic resonance imaging study that the perception of the McCollough effect correlates with increased activation in the lingual and fusiform gyriùextrastriate visual areas that have been implicated in color perception in humans.     

Measuring the bandwagon effect: Development of a generalized bandwagon luxury motivation scale

This study presents a reliable, valid, and generalizable four-item unidimensional scale that captures general bandwagon luxury motivation. After a thorough review of the bandwagon luxury literature, the authors developed an initial set of items which were then reviewed by academic experts. The scale was tested in a series of four studies to refine the scale and demonstrate its reliability and validity: Study 1 was conducted with a student sample in the Southeast, Study 2 with a student referral sample of adults in the Midwest, Study 3 with a national Qualtrics panel sample in the United States, and Study 4 with another national Qualtrics panel sample in the United States that included only those who had bought or consumed a luxury product in the past 12 months. Study 4 was done to corroborate the evidence from Study 3 with a sample of luxury consumers. The generalized bandwagon luxury motivation scale is positively related to status consumption motivation, congruity with one's internal self, a preference for visible luxury brands, and conspicuous consumption. It is negatively related to the inconspicuous luxury motivation of being unknown to the masses and independent self-construal. This research contributes to the literature by developing a generalized scale to measure the luxury bandwagon effect that is not limited to one luxury product domain.     

Understanding allies’ participation in social change: A multiple perspectives approach

The introduction to the EJSP special issue brings together recent literature on allyship. We present and discuss different definitions of allyship and highlight a multiple perspectives approach to understanding the predictors and consequences of allyship. This approach suggests that engagement in allyship can be driven by egalitarian and non-egalitarian motivations and that the behaviours identified as allyship can have different meanings, causes and consequences depending on whether researchers take into account the allies’ perspective or the disadvantaged groups’ perspective. We use this approach as an organizing principle to identify themes that emerge in the papers included in this special issue. We start with four papers that consider the perspective of the advantaged group, followed by two papers that consider the perspective of the disadvantaged group. Finally, we introduce two theoretical papers that examine the relations between disadvantaged groups and allies, and we set out directions for future research.     

Where there is a way, is there a will? The effect of future choices on self-control

Choices often involve self-control conflicts such that options that are immediately appealing are less desirable in the long run. In the current research, the authors examine how viewing such a choice as one of a series of similar future choices rather than as an isolated decision decreases the preference for items requiring self-control. The authors show that (a) in a choice between a vice and a virtue, the share choosing vice increases when the decision is presented as one of a series of similar future choices versus when the same choice is viewed in isolation, and (b) the overall share choosing a vice increases when decisions are seen in connection with similar future choices. The findings contrast with the general wisdom that broader choice frames lead to the exercise of greater self-control. The authors propose that the context of similar future choices allows people to optimistically believe that they will choose a virtue in the future choice and hence provides them with a guilt-reducing justification to not exercise self-control in the present.