The Impact of Item Misspecification and Dichotomization on Class and Parameter Recovery in LCA of Count Data

Mixture analysis of count data has become increasingly popular among researchers of substance use, behavioral analysis, and program evaluation. However, this increase in popularity seems to have occurred along with adoption of some conventions in model specification based on arbitrary heuristics that may impact the validity of results. Findings from a systematic review of recent drug and alcohol publications suggested count variables are often dichotomized or misspecified as continuous normal indicators in mixture analysis. Prior research suggests that misspecifying skewed distributions of continuous indicators in mixture analysis introduces bias, though the consequences of this practice when applied to count indicators has not been studied. The present work describes results from a simulation study examining bias in mixture recovery when count indicators are dichotomized (median split; presence vs. absence), ordinalized, or the distribution is misspecified (continuous normal; incorrect count distribution). All distributional misspecifications and methods of categorizing resulted in greater bias in parameter estimates and recovery of class membership relative to specifying the true distribution, though dichotomization appeared to improve class enumeration accuracy relative to all other specifications. Overall, results demonstrate the importance of accurately modeling count indicators in mixture analysis, as misspecification and categorizing data can distort study outcomes.     

The contagious impact of playing violent video games on aggression: Longitudinal evidence

Meta-analyses have shown that violent video game play increases aggression in the player. The present research suggests that violent video game play also affects individuals with whom the player is connected. A longitudinal study (N = 980) asked participants to report on their amount of violent video game play and level of aggression as well as how they perceive their friends and examined the association between the participant's aggression and their friends’ amount of violent video game play. As hypothesized, friends’ amount of violent video game play at Time 1 was associated with the participant's aggression at Time 2 even when controlling for the impact of the participant's aggression at Time 1. Mediation analyses showed that friends’ aggression at Time 1 accounted for the impact of friends’ amount of violent video game play at Time 1 on the participant's aggression at Time 2. These findings suggest that increased aggression in video game players has an impact on the player's social network.     

Terror in time: extending culturomics to address basic terror management mechanisms

Building on Google's efforts to scan millions of books, this article introduces methodology using a database of annual word frequencies of the 40,000 most frequently occurring words in the American literature between 1800 and 2009. The current paper uses this methodology to replicate and identify terror management processes in historical context. Variation in frequencies of word usage of constructs relevant to terror management theory (e.g. death, worldview, self-esteem, relationships) are investigated over a time period of 209 years. Study 1 corroborated previous TMT findings and demonstrated that word use of constructs related to death and of constructs related to patriotism and romantic relationships significantly co-vary over time. Study 2 showed that the use of the word “death” most strongly co-varies over time with the use of medical constructs, but also co-varies with the use of constructs related to violence, relationships, religion, positive sentiment, and negative sentiment. Study 3 found that a change in the use of death related words is associated with an increase in the use of fear related words, but not in anxiety related words. Results indicate that the described methodology generates valuable insights regarding terror management theory and provide new perspectives for theoretical advances.     

Positive and negative affect and well-being in cardiac patients and their spouses: the mediating role of illness representations

Objective: The aim of this study was to examine whether illness representations of control and consequences mediate the relation of cardiac patients’ affect to well-being. A further aim was to examine this indirect relationship at a dyadic level (i.e. patient and spouse). Design and main outcome measures: One hundred and four patients with a cardiovascular disease and their spouses participated in the study. Positive and negative affect was assessed at baseline; illness representations were assessed 2 months later, and physical and psychological well-being 4 months later. Results: Illness representations generally mediated the impact of patients’ and spouses’ affect on well-being, while several actor and partner effects were found. However, it was only positive affect that was indirectly related to well-being, while the representations of personal and treatment control chiefly acted as mediators. The effects were stronger for patients than spouses, as well as for physical well-being. Conclusion: The results underline the strong connection between illness-related self-regulation and the overall person/environment interaction as depicted by affect. They also indicate the need to integrate theories on adaptation to illness, with models describing adaptation of couples to stressful conditions, and specific theories about the role of emotion in adaptation to illness.     

Using Dynamic Panel Models to Study Age‐related Differences and Time‐related Changes in Personality

Along with an increasing interest in the plasticity and role of personality across the adult lifespan comes the need for a diverse set of innovative statistical approaches to study it. With this paper, we set out to illustrate some of the possibilities and challenges in modelling age‐related differences and time‐related changes in personality psychology by means of dynamic panel models. To this end, we first distinguish between the study of age‐related differences and time‐related changes and demonstrate how the treatment of age and time as either discrete or continuous variables implies important modelling choices. Second, we present a selection of four example cases that address the topic of age moderation in diverse matters and with different objectives. Based on our cross‐tabulation of age and time as discrete and continuous variables, the first two example cases represent fairly well‐established models (cases A and B), whereas the remaining cases are used to illustrate current developments in the field (cases C and D). We close the paper with some final remarks on current limitation and future research directions. © 2019 European Association of Personality Psychology     

A Systematic Review of Online Response Rates in Four Counseling Journals

This systematic review of articles published in 4 counseling journals found 207 articles that used online recruitment, of which 98 (47.3%) reported a response rate. These 98 studies collectively contained 22,466 individual participants. Results showed that nearly one third of all empirical articles used online recruitment, and the average response rate was 34.2% (SD = 22.6). Response rates are further described by journal, population, research methodology, and recruitment strategy. Researcher‐reported issues with online recruitment and data collection were also analyzed qualitatively, and recommendations for researchers are discussed.     

Self‐concept clarity and relationship satisfaction at the dyadic level

Self‐concept clarity is an individual resource that is associated with couple relationship well‐being. In two dyadic studies, the authors investigated whether and how self‐concept clarity has implications for both partners' relationship satisfaction. Study 1 tested and supported the hypothesis that self‐concept clarity concurrently predicts own and partner's relationship satisfaction through couple identity in a sample of 202 dating couples. Study 2 tested and supported the hypothesis that self‐concept clarity predicts longitudinal change in own and partner's relationship satisfaction through positive (i.e., supportive and common) dyadic coping behaviors in a sample of 97 married couples. The findings clarify and expand the benefits of self‐concept clarity for partners' relational well‐being.     

魅力型领导与军事团队绩效：军政双主官的交互效应及士气的中介

我军广泛实行分工负责军事和政治工作的平级双领导体制,两名主官的相互作用可能产生额外影响效果。本研究在“连”这一双领导军事团队中,构建了一个以士气为中介的交互效应模型,考察连长和指导员的魅力型领导对连队绩效的影响。对350名军校士兵学员进行问卷调查,结果显示：（1）连长和指导员的魅力型领导对连队绩效具有交互效应。（2）士气在连长、指导员的魅力型领导与连队绩效之间均具有中介效应。（3）连长、指导员的魅力型领导对连队绩效的交互效应受到士气的中介。（4）双主官的交互效应为补偿式：与低魅力型领导搭档时,高魅力型领导的积极效果凸显,但两位高魅力型领导的协同效应不显著。