Friend influence over adolescent problem behaviors as a function of relative peer acceptance: to be liked is to be emulated

Friend influence over alcohol intoxication and delinquent behavior was examined as a function of relative peer acceptance in a 3-year study of Swedish youth (N = 184 girls, 145 boys). Participants were in the first year of secondary school (7th grade, M = 11.7 years old) or the first year of high school (10th grade, M = 15.3 years old) at the outset. Friends resembled one another before the friendship; resemblances were even greater after the friendship began. Resemblances continued to grow among those who remained friends one year later, but declined among those whose friendships dissolved. Partners were not equally responsible for increases in similarity. In stable friendships, the more accepted partner exerted greater influence over the less accepted partner, such that the greatest increases in problem behaviors were found among less accepted youth whose friends had higher initial levels of delinquency and alcohol intoxication. Unstable friends resembled random pairs of youth in that more- and less-accepted partners were comparably uninfluential.     

Consequence Mining

The standard semantic definition of consequence with respect to a selected set X of symbols, in terms of truth preservation under replacement (Bolzano) or reinterpretation (Tarski) of symbols outside X, yields a function mapping X to a consequence relation \(\Rightarrow_X\). We investigate a function going in the other direction, thus extracting the constants of a given consequence relation, and we show that this function (a) retrieves the usual logical constants from the usual logical consequence relations, and (b) is an inverse to—more precisely, forms a Galois connection with—the Bolzano–Tarski function.     

Development of a Facebook Addiction Scale

The Bergen Facebook Addiction Scale (BFAS), initially a pool of 18 items, three reflecting each of the six core elements of addiction (salience, mood modification, tolerance, withdrawal, conflict, and relapse), was constructed and administered to 423 students together with several other standardized self-report scales (Addictive Tendencies Scale, Online Sociability Scale, Facebook Attitude Scale, NEO-FFI, BIS/BAS scales, and Sleep questions). That item within each of the six addiction elements with the highest corrected item-total correlation was retained in the final scale. The factor structure of the scale was good (RMSEA = .046, CFI = .99) and coefficient alpha was .83. The 3-week test-retest reliability coefficient was .82. The scores converged with scores for other scales of Facebook activity. Also, they were positively related to Neuroticism and Extraversion, and negatively related to Conscientiousness. High scores on the new scale were associated with delayed bedtimes and rising times.     

Development of a work addiction scale

Andreassen, C. S., Griffiths, M. D., Hetland, J. & Pallesen, S. (2012). Development of a work addiction scale. Scandinavian Journal of Psychology 53, 265–272. Research into excessive work has gained increasing attention over the last 20 years. Terms such as “workaholism,”“work addiction” and “excessive work” have been used interchangeably. Given the increase in empirical research, this study presents the development of the Bergen Work Addiction Scale (BWAS), a new psychometrically validated scale for the assessment of work addiction. A pool of 14 items, with two reflecting each of seven core elements of addiction (i.e., salience, mood modification, tolerance, withdrawal, conflict, relapse, and problems) was initially constructed. The items were then administered to two samples, one recruited by a web survey following a television broadcast about workaholism (n = 11,769) and one comprising participants in the second wave of a longitudinal internet‐based survey about working life (n = 368). The items with the highest corrected item‐total correlation from within each of the seven addiction elements were retained in the final scale. The assumed one‐factor solution of the refined seven‐item scale was acceptable (root mean square error of approximation = 0.077, Comparative Fit Index = 0.96, Tucker‐Lewis Index = 0.95) and the internal reliability of the two samples were 0.84 and 0.80, respectively. The scores of the BWAS converged with scores on other workaholism scales, except for a Work Enjoyment subscale. A suggested cut‐off for categorization of workaholics showed good discriminative ability in terms of working hours, leadership position, and subjective health complaints. It is concluded that the BWAS has good psychometric properties.     

The effect of kurtosis on the power of two test statistics in covariance structure analysis

We study the effect of excess kurtosis on the non-centrality parameters of the rescaled and the residual-based test statistics for covariance structure models. The analysis is based on population matrices and parameters, which eliminates the sampling variability inherent in simulation studies. We show that the non-centrality parameters, and consequently the asymptotic power, decrease as kurtosis in the data increases. Examples are provided to compare this decrease for the two test statistics, and to illustrate how substantial it is.     

Individual differences in timing of discrete and continuous movements: a dimensional approach

This study investigated aspects of individual differences in timing of continuous and discontinuous movements to different pacing signals (auditory or visual), pacing intervals (500, 650, 800, 950 ms), and across effectors (dominant versus non-dominant hand). Correlation and principal component analysis demonstrated that a single statistical dimension accounted for up to 60 % of the explained variance in discontinuous tasks and 25 % of the variance in continuous tasks, when applied to performance obtained from tasks conducted with different effectors and at different pacing rates. Correlation analysis of factor scores representing effector and rate independent task performances showed that timing of discrete or continuous movements can be associated with modality independent mechanisms. Timing variability from discrete and continuous trials was not significantly correlated. This study goes beyond previous correlational work on individual differences in discrete and continuous movements, demonstrating that individual differences in discrete (event-based) or continuous (emergent) motor timing tasks can be modeled as distinctive statistical components with dissimilar capability to capture effector, rate, and modality independent variance.     

Treating Procrastination Using Cognitive Behavior Therapy: A Pragmatic Randomized Controlled Trial Comparing Treatment Delivered via the Internet or in Groups

Procrastination is a common problem among university students, with at least half of the population reporting great difficulties initiating or completing tasks and assignments. Procrastination can have a negative impact on course grades and the ability to achieve a university degree, but can also lead to psychological distress. Cognitive behavior therapy (CBT) is believed to reduce procrastination, but few studies have investigated its effectiveness in a regular clinical setting. The current study explored its effects using a pragmatic randomized controlled trial comparing treatment delivered during 8 weeks as self-guided CBT via the Internet (ICBT) or as group CBT. In total, 92 university students with severe procrastination were included in the study (registered as a clinical trial on Clinicaltrials.gov: NCT02112383). Outcome measures on procrastination, depression, anxiety, and well-being were distributed at pre- and posttreatment as well as 6-month follow-up. An outcome measure of procrastination was administered weekly. Linear mixed and fixed effects models were calculated, along with improvement and deterioration rates. The results showed large within-group effect sizes on procrastination, Cohen’s d of 1.29 for ICBT, 95% Confidence Interval (CI) [0.81, 1.74], and d of 1.24 for group CBT, 95% CI [0.76, 1.70], and small to moderate benefits for depression, anxiety, and well-being. In total, 33.7% were regarded as improved at posttreatment and 46.7% at follow-up. No differences between conditions were observed after the treatment period, however, participants in group CBT continued or maintained their improvement at follow-up, while participants in self-guided ICBT showed some signs of deterioration. The findings from the current study suggest that CBT might be an effective treatment for those struggling with severe procrastination, but that a group format may be better for some to sustain their benefits over time and that the clinical significance of the results need to be investigated further.     

Do Bettors Correctly Perceive Odds? Three Studies of How Bettors Interpret Betting Odds as Probabilistic Information

This paper reports on three studies investigating how accurately bettors (=people who regularly bet on sports events) interpret the probabilistic information implied by betting odds. All studies were based on data collected by web surveys prompting a total of 186 experienced bettors to convert sets of representative odds into frequency judgments. Bayesian statistical methods were used to analyze the data. From the results, the following conclusions were made: (i) On the whole, the bettors produced well‐calibrated judgments, indicating that they have realistic perceptions of odds. (ii) Bettors were unable to consciously adjust judgments for different margins. (iii) Although their interval judgments often covered the estimates implied by the odds, the bettors tended to overestimate the variation of expected profitable bets between months. The results are consistent with prior research showing that people tend to make accurate probability judgments when faced with tasks characterized by constant and clear feedback. Copyright © 2015 John Wiley & Sons, Ltd.