Bayesian inference with Stan: A tutorial on adding custom distributions

When evaluating cognitive models based on fits to observed data (or, really, any model that has free parameters), parameter estimation is critically important. Traditional techniques like hill climbing by minimizing or maximizing a fit statistic often result in point estimates. Bayesian approaches instead estimate parameters as posterior probability distributions, and thus naturally account for the uncertainty associated with parameter estimation; Bayesian approaches also offer powerful and principled methods for model comparison. Although software applications such as WinBUGS (Lunn, Thomas, Best, & Spiegelhalter, Statistics and Computing, 10, 325–337, 2000) and JAGS (Plummer, 2003) provide “turnkey”-style packages for Bayesian inference, they can be inefficient when dealing with models whose parameters are correlated, which is often the case for cognitive models, and they can impose significant technical barriers to adding custom distributions, which is often necessary when implementing cognitive models within a Bayesian framework. A recently developed software package called Stan (Stan Development Team, 2015) can solve both problems, as well as provide a turnkey solution to Bayesian inference. We present a tutorial on how to use Stan and how to add custom distributions to it, with an example using the linear ballistic accumulator model (Brown & Heathcote, Cognitive Psychology, 57, 153–178. doi: 10.1016/j.cogpsych.2007.12.002, 2008).     

Asian and Pacific Island American students' acculturation and etiology beliefs about typical counseling presenting problems

Asian American Pacific Island college students (N = 93) completed measures of acculturation and mental health worldview, in the form of beliefs about the likely causes of 24 typical counseling presenting problems. A criterion sample of 27 staff from 2 university counseling centers reported their beliefs about the most likely cause of the same 24 problems for a typical client. A response similarity index was calculated, with higher scores reflecting greater similarity between student and counselor mental health worldviews. Results suggest that higher acculturation was associated with greater level of match between the students' etiology beliefs and those of counselors. The greatest differences were observed for serious personal problems, whereas there was more belief convergence about causes of academic problems.     

Agent causation as a solution to the problem of action

My primary aim is to defend a nonreductive solution to the problem of action. I argue that when you are performing an overt bodily action, you are playing an irreducible causal role in bringing about, sustaining, and controlling the movements of your body, a causal role best understood as an instance of agent causation. Thus, the solution that I defend employs a notion of agent causation, though emphatically not in defence of an account of free will, as most theories of agent causation are. Rather, I argue that the notion of agent causation introduced here best explains how it is that you are making your body move during an action, thereby providing a satisfactory solution to the problem of action.     

Genetic and Environmental Pathways Underlying Personality Traits and Perceived Stress: Concurrent and Longitudinal Twin Studies

The present study examined the genetic and environmental etiology underlying the Big Five personality traits and perceived stress, concurrently and longitudinally. In study 1, we used the twin sample from the National Longitudinal Study of Adolescent to Adult Health (Add Health IV) data. The results indicated that about 70% of the association between the Big Five personality traits and perceived stress was due to genetic influences. In study 2, we used the twin sample from the Midlife in the United States Survey (MIDUS I and II) to examine the genetic and environmental influences underlying the longitudinal relations between the Big Five personality traits and perceived stress. The results suggested that continuity in perceived stress was primarily accounted for by genetic influences, and changes in perceived stress were mainly due to nonshared environmental influences. The continuity in the association between the five personality traits and perceived stress was largely accounted for by genetic factors, and nonshared environmental factors made greater contributions to changes in the association between personality traits and perceived stress. Among the Big Five personality traits, the genetic components in conscientiousness and neuroticism made substantial contributions to the genetic link between personality traits and perceived stress across both studies. Copyright © 2017 European Association of Personality Psychology     

Associations between evaluation anxiety,cognitive interference and performance on working memory tasks

According to Cognitive Interference Theory, evaluation anxiety leads to increased negative off‐task self‐dialogue which then results in diminished cognitive performance. Given that negative off‐task self‐dialogue is primarily verbal, the phonological loop and central executive components of the working memory system should be most affected by evaluation anxiety. Eighty‐eight participants were randomly assigned to receive evaluation anxiety inducing instructions or supportive instructions prior to administration of three tests (Digit Span, Visual Memory Span, and StroopColour‐Word) that measured the phonological loop, visuospatial sketchpad, and central executive components of working memory. Measures of evaluation anxiety and negative off‐task self‐dialogue were obtained during and after testing. Results showed that participants receiving anxiety inducing instructions reported significantly more evaluation anxiety and off‐task self‐dialogue. They also had significantly lower performance on the Digit Span Test and the StroopColour‐Word Test. Negative off‐task self‐dialogue also mediated the relationship between evaluation anxiety and performance on the Digit Span Test. Copyright © 2011 John Wiley & Sons, Ltd.     

Internalization of Appearance Ideals and Cosmetic Surgery Attitudes: A Test of the Tripartite Influence Model of Body Image

The Tripartite Influence Model of Body Image was adapted to examine the role of body satisfaction, perceived pressure to have cosmetic surgery, and internalization of societal appearance ideals in understanding cosmetic surgery attitudes. Participants were 2,048 men (N?=?445) and women (N?=?1,603) American college students from Florida who completed a range of measures that assessed levels of body satisfaction, perceived appearance pressures, internalization of appearance standards, and cosmetic surgery attitudes. A structural equation model was used to test hypothesized relations independently for men and women. Results indicated a moderate-good fit to the data, with both internalization and body satisfaction mediating the effect of perceived pressures on cosmetic surgery attitudes. Invariance testing revealed significant differences in pathway estimates between samples of men and women. The findings offer further support for the Tripartite Influence Model of Body Image and indicate potential factors that may influence cosmetic surgery attitudes.     

Work–family interpersonal capitalization: Sharing positive work events at home

In a 3-week experience-sampling study of 52 full-time employees, the authors investigated the within-individual relationships among positive work events, affective states, and job satisfaction. They also examined the influence of work–family interpersonal capitalization (sharing work events with one’s spouse or partner at home) on employees’ job and relationship satisfaction. Results revealed that positive events influenced job satisfaction through positive affect, and work–family interpersonal capitalization on the most positive work event of the day positively impacted job satisfaction over and above the effects of the event’s pleasantness and of the number of other positive work events experienced that day.     

Practicing What You Preach: Infidelity Attitudes as a Predictor of Fidelity

The current studies used the Perceptions of Dating Infidelity Scale (PDIS), which identifies attitudes toward three types of behaviors indicative of cheating: Ambiguous, Deceptive, and Explicit behaviors, to predict actual infidelity behaviors. Participants reported their attitude toward these behaviors and then reported their willingness to engage in these behaviors with a hypothetical target (Study 1) and reported actually engaging in these behaviors over the course of one month (Study 2). Study 1 showed that attitudes for Ambiguous and Deceptive behaviors significantly predict a willingness to engage in these behaviors with a hypothetical target. Study 2 showed that attitudes toward Ambiguous behaviors significantly predict actual engagement in Ambiguous behaviors during the course of one month.     

Dispelling a few false-positives: A reply to MacGregor and McNamee on doping

McGregor and MacNamee recently, in this journal, offered several criticisms of an earlier article in which I attempted to refute a number of arguments for the claim that doping in sports is morally wrong. Their criticisms are numerous, but focus on four domains. First, they sketch a view on which the risk profiles of different sports may make doping permissible in some and impermissible in others. Second, they suggest that my criticisms of safety-based arguments assume that doping opponents are bent on harm elimination, rather than harm management. Finally, they offer two methodological criticisms, the first pertaining to my use of analogical arguments, and the second pertaining to the general difficulties of making revisionist arguments in ethics. I defend my criticisms of safety-based arguments by showing that these do not rest on the assumptions McGregor and MacNamee attribute to me and by noting that their own view about the variable relevance of safety considerations is underdeveloped. As for their methodological arguments, I endeavor to show that these are misplaced, in that they either rest on misinterpretations of my earlier article or on an excessively high standard for ethical argumentation.