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Concept: Structural equation modeling


Traditional screen time (e.g. TV and videogaming) has been linked to sleep problems and poorer developmental outcomes in children. With the advent of portable touchscreen devices, this association may be extending down in age to disrupt the sleep of infants and toddlers, an age when sleep is essential for cognitive development. However, this association has not been demonstrated empirically. This study aims to examine whether frequency of touchscreen use is associated with sleep in infants and toddlers between 6 and 36 months of age. An online survey was administered to 715 parents reporting on child media use (daily exposure to TV and use of touchscreens), sleep patterns (night-time and daytime sleep duration, sleep onset - time to fall asleep, and frequencies of night awakenings). Structural equation models controlling for age, sex, TV exposure and maternal education indicated a significant association between touchscreen use and night-time sleep, daytime sleep and sleep onset. No significant effect was observed for the number of night awakenings. To our knowledge, this is the first report linking the use of touchscreen with sleep problems in infants and toddlers. Future longitudinal studies are needed to clarify the direction of effects and the mechanisms underlying these associations using detailed sleep tracking.

Concepts: Infant, Sleep, Sleep disorder, Circadian rhythm, Narcolepsy, Structural equation modeling, Sleep hygiene


The global epidemic of obesity and physical inactivity may have detrimental implications for young people’s cognitive function and academic achievement. This prospective study investigated whether childhood motor function predicts later academic achievement via physical activity, fitness, and obesity. The study sample included 8,061 children from the Northern Finland Birth Cohort 1986, which contains data about parent-reported motor function at age 8 y and self-reported physical activity, predicted cardiorespiratory fitness (cycle ergometer test), obesity (body weight and height), and academic achievement (grades) at age 16 y. Structural equation models with unstandardized (B) and standardized (β) coefficients were used to test whether, and to what extent, physical activity, cardiorespiratory fitness, and obesity at age 16 mediated the association between childhood motor function and adolescents' academic achievement. Physical activity was associated with a higher grade-point average, and obesity was associated with a lower grade-point average in adolescence. Furthermore, compromised motor function in childhood had a negative indirect effect on adolescents' academic achievement via physical inactivity (B = -0.023, 95% confidence interval = -0.031, -0.015) and obesity (B = -0.025, 95% confidence interval = -0.039, -0.011), but not via cardiorespiratory fitness. These results suggest that physical activity and obesity may mediate the association between childhood motor function and adolescents' academic achievement. Compromised motor function in childhood may represent an important factor driving the effects of obesity and physical inactivity on academic underachievement.

Concepts: Obesity, Overweight, Interval finite element, Adolescence, Confidence interval, Prediction interval, Physical fitness, Structural equation modeling


The mechanisms underlying hyperarousal, the key symptom of insomnia, have remained elusive, hampering cause-targeted treatment. Recently, restless rapid-eye-movement (REM) sleep emerged as a robust signature of sleep in insomnia. Given the role of REM sleep in emotion regulation, we hypothesized that restless REM sleep could interfere with the overnight resolution of emotional distress, thus contributing to accumulation of arousal. Participants (n = 1,199) completed questionnaires on insomnia severity, hyperarousal, self-conscious emotional distress, and thought-like nocturnal mentation that was validated to be a specific proxy for restless REM sleep (selective fragmentation: R = 0.57, P < 0.001; eye movement density: R = 0.46, P < 0.01) in 32 polysomnographically assessed participants. The experience of distress lasting overnight increased with insomnia severity (β = 0.29, P < 10(-23)), whereas short-lasting distress did not (β = -0.02, P = 0.41). Insomnia severity was associated with hyperarousal (β = 0.47, P < 10(-63)) and with the thought-like nocturnal mentation that is specifically associated with restless REM sleep (β = 0.31, P < 10(-26)). Structural equation modeling showed that 62.4% of the association between these key characteristics of insomnia was mediated specifically by reduced overnight resolution of emotional distress. The model outperformed all alternative mediation pathways. The findings suggest that restless REM sleep reflects a process that interferes with the overnight resolution of distress. Its accumulation may promote the development of chronic hyperarousal, giving clinical relevance to the role of REM sleep in emotion regulation in insomnia, depression, and posttraumatic stress disorder.

Concepts: Psychology, Sleep, The Key, Cognitive behavioral therapy, Stress, Emotion, Anxiety disorder, Structural equation modeling


Perceived addiction to Internet pornography is increasingly a focus of empirical attention. The present study examined the role that religious belief and moral disapproval of pornography use play in the experience of perceived addiction to Internet pornography. Results from two studies in undergraduate samples (Study 1, N = 331; Study 2, N = 97) indicated that there was a robust positive relationship between religiosity and perceived addiction to pornography and that this relationship was mediated by moral disapproval of pornography use. These results persisted even when actual use of pornography was controlled. Furthermore, although religiosity was negatively predictive of acknowledging any pornography use, among pornography users, religiosity was unrelated to actual levels of use. A structural equation model from a web-based sample of adults (Study 3, N = 208) revealed similar results. Specifically, religiosity was robustly predictive of perceived addiction, even when relevant covariates (e.g., trait self-control, socially desirable responding, neuroticism, use of pornography) were held constant. In sum, the present study indicated that religiosity and moral disapproval of pornography use were robust predictors of perceived addiction to Internet pornography while being unrelated to actual levels of use among pornography consumers.

Concepts: Faith, Future, Addiction, Religion, Internet, Structural equation modeling, Pornography, Pornography addiction


The role of emotional disgust and disgust sensitivity in moral judgment and decision-making has been debated intensively for over 20 years. Until very recently, there were two main evolutionary narratives for this rather puzzling association. One of the models suggest that it was developed through some form of group selection mechanism, where the internal norms of the groups were acting as pathogen safety mechanisms. Another model suggested that these mechanisms were developed through hygiene norms, which were piggybacking on pathogen disgust mechanisms. In this study we present another alternative, namely that this mechanism might have evolved through sexual disgust sensitivity. We note that though the role of disgust in moral judgment has been questioned recently, few studies have taken disgust sensitivity to account. We present data from a large sample (N = 1300) where we analyzed the associations between The Three Domain Disgust Scale and the most commonly used 12 moral dilemmas measuring utilitarian/deontological preferences with Structural Equation Modeling. Our results indicate that of the three domains of disgust, only sexual disgust is associated with more deontological moral preferences. We also found that pathogen disgust was associated with more utilitarian preferences. Implications of the findings are discussed.

Concepts: Bacteria, Evolution, Ethics, Model, Morality, Choice, Group selection, Structural equation modeling


BACKGROUND: Research in the United States and the United Kingdom indicates that drinking before going out (commonly called “predrinking”) is common among young people and associated with increased harm. On the basis of Swiss data, this study investigates differences in alcohol consumption and adverse or risky outcomes for evenings when persons consumed alcohol before going to a licensed premise (i.e., predrinking), drank on-premise only, or drank off-premise only. METHODS: Using the recently developed Internet-based cell phone-optimized assessment technique (ICAT), alcohol consumption and drinking location were assessed at 6 time points (5 pm to the next morning) on Thursdays, Fridays, and Saturdays over 5 consecutive weeks by means of participants' cell phones. Overall, 7,828 assessments provided by 183 young adults (53.0% women, mean age [SD] = 23.1 [3.1]) on 1,441 evenings were analyzed by means of cluster-adjusted means and proportion tests and of multilevel structural equation models. The extent to which alcohol consumption mediated the association between predrinking and adverse outcomes was also examined. RESULTS: Higher alcohol consumption occurred on evenings with predrinking (7.1 drinks on average) compared with on-premise only (4.2 drinks) and off-premise only (4.3 drinks) evenings. Adverse outcomes occurred more often on evenings with predrinking (with 23.8% of predrinking nights involving at least 1 outcome) than on evenings with on-premise drinking only (13.9%) and off-premise drinking only (12.0%). Predrinking was indirectly associated with adverse outcomes, mediated by larger amounts of alcohol consumed in the evening. CONCLUSIONS: Because of its association with heavier consumption and related adverse outcomes, predrinking, especially combined with on-premise drinking, represents a major target for prevention. Educational interventions as well as structural measures, such as reduction in late-night off-sale opening hours, and staff training in responsible beverage service, are needed to prevent high total consumption and related adverse consequences among young people.

Concepts: Alcohol, United States, United Kingdom, Alcoholic beverage, Drinking culture, Structural equation modeling, Drink, Kefir


The negative consequences of peer victimization on psychosocial adjustment are well documented. The consequences, however, may depend on who the bullies are. In this study, we examined the consequences of same- versus other-sex victimization. The sample consisted of 4,941 Finnish adolescents (ages 14-15; 47.7% boys). We used structural equation modeling to examine both concurrent and longitudinal associations of same- and other-sex victimization with depression, negative perception of peers, and social self-esteem. Both same- and other-sex victimization were related to psychosocial adjustment. Concurrently, the victimization experiences with same-sex peers in particular were associated with generalized cognitions about peers, whereas being bullied by other-sex peers was related to adolescents' social self-esteem more strongly than victimization by same-sex peers. The longitudinal associations, in turn, showed that only being bullied by boys had carry-over effects on girls' adjustment. Other-sex victimization can have serious consequences especially on girls' psychosocial adjustment. [Supplementary material is available for this article. Go to the publisher’s online edition of the Journal of Clinical Child & Adolescent Psychology for the following supplemental resource: Complementary information on model fit indices and the nested model chi-square difference tests.].

Concepts: Psychology, Following, Model, Adolescence, The Adolescents, Peer group, Structural equation modeling, Bullying


In covariance structure analysis, two-stage least-squares (2SLS) estimation has been recommended for use over maximum likelihood estimation when model misspecification is suspected. However, 2SLS often fails to provide stable and accurate solutions, particularly for structural equation models with small samples. To address this issue, a regularized extension of 2SLS is proposed that integrates a ridge type of regularization into 2SLS, thereby enabling the method to effectively handle the small-sample-size problem. Results are then reported of a Monte Carlo study conducted to evaluate the performance of the proposed method, as compared to its nonregularized counterpart. Finally, an application is presented that demonstrates the empirical usefulness of the proposed method.

Concepts: Regression analysis, Sample size, Estimation theory, Econometrics, Maximum likelihood, Fisher information, Structural equation modeling, Generalized method of moments


Differential equation models can be used to describe the relationships between the current state of a system of constructs (e.g., stress) and how those constructs are changing (e.g., based on variable-like experiences). The following article describes a differential equation model based on the concept of a reservoir. With a physical reservoir, such as one for water, the level of the liquid in the reservoir at any time depends on the contributions to the reservoir (inputs) and the amount of liquid removed from the reservoir (outputs). This reservoir model might be useful for constructs such as stress, where events might “add up” over time (e.g., life stressors, inputs), but individuals simultaneously take action to “blow off steam” (e.g., engage coping resources, outputs). The reservoir model can provide descriptive statistics of the inputs that contribute to the “height” (level) of a construct and a parameter that describes a person’s ability to dissipate the construct. After discussing the model, we describe a method of fitting the model as a structural equation model using latent differential equation modeling and latent distribution modeling. A simulation study is presented to examine recovery of the input distribution and output parameter. The model is then applied to the daily self-reports of negative affect and stress from a sample of older adults from the Notre Dame Longitudinal Study on Aging. (PsycINFO Database Record © 2013 APA, all rights reserved).

Concepts: Cybernetics, Model, Differential equation, All rights reserved, Input, Structural equation modeling, Output, Input/output


This 6 month prospective study systematically tested some multivariate models that advanced the understanding of the psychological mechanisms underlying Internet addiction and psychosocial maladjustment. On the basis of previous theories, avoidant coping and coping inflexibility were proposed as underlying mechanisms. Participants were 271 Chinese undergraduates (75% women, Mage=20.49) who took part in both phases of this study. Structural equation modeling was performed to obtain the best fit models for both the cross-sectional and the prospective data. The cross-sectional model testing revealed statistically significant mediating effects for both avoidant coping (β=0.149 [95% CI 0.071-0.226], p=0.002) and coping flexibility (β=0.048 [95% CI 0.013-0.081], p=0.032). The prospective model testing further showed that avoidant coping mediated the relationship between Internet addiction and Time 2 psychosocial maladjustment (β=0.141 [95% CI 0.065-0.216], p=0.005), as well as that between coping flexibility and Time 2 psychosocial maladjustment (β=-0.096 [95% CI -0.161 to -0.031], p=0.015). This study was the first to establish theory-driven models, which unveiled an inflexible, avoidant coping style as psychological mechanisms that explained the link between Internet addiction and psychosocial maladjustment.

Concepts: Statistics, Statistical significance, Econometrics, Addiction, Model, Statistical hypothesis testing, Structural equation modeling, Multivariate