Evaluating expectations about negative emotional states of aggressive boys using Bayesian model selection

Researchers often have expectations about the research outcomes in regard to inequality constraints between, e.g., group means. Consider the example of researchers who investigated the effects of inducing a negative emotional state in aggressive boys. It was expected that highly aggressive boys would, on average, score higher on aggressive responses toward other peers than moderately aggressive boys, who would in turn score higher than nonaggressive boys. In most cases, null hypothesis testing is used to evaluate such hypotheses. We show, however, that hypotheses formulated using inequality constraints between the group means are generally not evaluated properly. The wrong hypotheses are tested, i.e.. the null hypothesis that group means are equal. In this article, we propose an innovative solution to these above-mentioned issues using Bayesian model selection, which we illustrate using a case study.     

Des raisons d'être d'une argumentation rhétorique selon Aristote

The main purpose of this paper is to explore the reasons Aristotle gives for being able to use rhetorical argumentation, which is obviously not a scientific mode of expression. This faculty which was condemned by Plato as lacking morality, is paradoxically regarded by Aristotle as necessary on moral grounds. For, according to him, it would be blameworthy to keep silent when being verbally assailed. The necessity of rhetoric is, however, more deeply founded. First, because justice has to be saved from its enemies in the City's courts of law. Secondly, because everyone has to be convicted to follow in practice the rules of the City's laws and such a conviction, in the case of the multitude, cannot be obtained by the means of scientific arguments. Thirdly and above all, because, in forensic disputes, characteristics of free political societies, the demagogic power, which regularly leads to tyrannical regimes, can only be avoided by the weapons of rhetoric. From these explanations, one does see that rhetoric, for Aristotle, seems to be the necessary substitute for ancient and traditional instruments securing obedience to legal justice, i.e. myths and pure constraint or coercion. In civilized and free political communities, rhetoric is required for civilization and freedom.

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Des raisons d'être d'une argumentation rhétorique selon Aristote

     

Personality types in adolescence: change and stability and links with adjustment and relationships: a five-wave longitudinal study

We examined change and stability of the 3 personality types identified by Block and Block (1980) and studied their links with adjustment and relationships. We used data from a 5-wave study of 923 early-to-middle and 390 middle-to-late adolescents, thereby covering the ages of 12-20 years. In Study 1, systematic evidence for personality change was found, in that the number of overcontrollers and undercontrollers decreased, whereas the number of resilients increased. Undercontrol, in particular, was found to peak in early-to-middle adolescence. We also found substantial stability of personality types, because 73.5% of the adolescents had the same personality type across the 5 waves. Personality change was mainly characterized by 2 transitions: overcontrol → resiliency and undercontrol → resiliency. The transitional analyses implied that the resilient type serves more often as the end point of personality development in adolescence than do overcontrol and undercontrol. Analyses of the personality type trajectories also revealed that the majority of adolescents who change personality type across 5 years made only 1 transition. Study 2 revealed systematic differences between resilients and overcontrollers in anxiety. Stable resilients were less anxious over time than were stable overcontrollers. Further, change from overcontrol to the resilient type was accompanied by decreases in anxiety, whereas change from the resilient type to overcontrol was accompanied by an increase in anxiety. Similarly, systematic differences between personality types were found in the formation of intimate relationships.     

Bayesian model selection of informative hypotheses for repeated measurements

When analyzing repeated measurements data, researchers often have expectations about the relations between the measurement means. The expectations can often be formalized using equality and inequality constraints between (i) the measurement means over time, (ii) the measurement means between groups, (iii) the means adjusted for time-invariant covariates, and (iv) the means adjusted for time-varying covariates. The result is a set of informative hypotheses. In this paper, the Bayes factor is used to determine which hypothesis receives most support from the data. A pivotal element in the Bayesian framework is the specification of the prior. To avoid subjective prior specification, training data in combination with restrictions on the measurement means are used to obtain so-called constrained posterior priors. A simulation study and an empirical example from developmental psychology show that this prior results in Bayes factors with desirable properties.     

A prior predictive loss function for the evaluation of inequality constrained hypotheses

In many types of statistical modeling, inequality constraints are imposed between the parameters of interest. As we will show in this paper, the DIC (i.e., posterior Deviance Information Criterium as proposed as a Bayesian model selection tool by Spiegelhalter, Best, Carlin, & Van Der Linde, 2002) fails when comparing inequality constrained hypotheses. In this paper, we will derive the prior DIC and show that it also fails when comparing inequality constrained hypotheses. However, it will be shown that a modification of the prior predictive loss function that is minimized by the prior DIC renders a criterion that does have the properties needed in order to be able to compare inequality constrained hypotheses. This new criterion will be called the Prior Information Criterion (PIC) and will be illustrated and evaluated using simulated data and examples. The PIC has a close connection with the marginal likelihood in combination with the encompassing prior approach and both methods will be compared. All in all, the main message of the current paper is: (1) do not use the classical DIC when evaluating inequality constrained hypotheses, better use the PIC; and (2) the PIC is considered a proper model selection tool in the context of evaluating inequality constrained hypotheses.     

Costs and Benefits of Bullying in the Context of the Peer Group: A Three Wave Longitudinal Analysis

Whereas previous research has shown that bullying in youth is predictive of a range of negative outcomes later in life, the more proximal consequences of bullying in the context of the peer group at school are not as clear. The present three-wave longitudinal study followed children (N?=?394; 53 % girls; M _age?=?10.3 at Time 1) from late childhood into early adolescence. Joint trajectory analyses were used to examine the dynamic prospective relations between bullying on the one hand, and indices tapping perceived popularity, peer-reported social acceptance, self-perceived social competence, and internalizing symptoms on the other. Results show that although young bullies may be on a developmental path that in the long run becomes problematic, from the bullies’ perspective in the shorter term personal advantages outweigh disadvantages. High bullying is highly positively related to high social status as indexed by perceived popularity. Although bullies are not very high in peer-rated social acceptance, most are not very low either. Moreover, bullies do not demonstrate elevated internalizing symptoms, or problems in the social domain as indexed by self-perceived social competence. As bullying yields clear personal benefits for the bullies without strong costs, the findings underscore the need for interventions targeting mechanisms that reward bullying (198 words).     

The effectiveness of a proactive coping intervention targeting self-management in diabetes patients

Objective: The study’s aim was to investigate psychological, behavioral and medical long-term outcomes of an existing self-management intervention targeting the development of proactive coping skills (e.g. goal setting and identifying barriers) in type 2 diabetes patients. The study aimed to replicate prior research showing the intervention’s effectiveness, and to extend it by (a) adding booster sessions and (b) prolonging the period of follow-up measurement to capture long-term effects.

Design/outcome measures: A total of 141 type 2 diabetes patients were included in the intervention. The intervention employed a 5-step approach to target proactive coping skills. Psychological (e.g. proactive coping and self-efficacy) and behavioural variables (e.g. self-care, diet and physical activity) were assessed at baseline (T1), after the initial phase of the intervention (T2), after the booster phase (T3) and at follow-up (T4), comprising a total period of 15 months. Medical variables were assessed at T1 and T4.

Results: Employing piecewise Latent Growth Curve Modelling, results showed that participants improved on all psychological and behavioural variables during the initial phase and maintained these improvements over 12 months. The booster phase yielded no further improvements. Mixed findings were obtained on medical outcomes.

Conclusion: The original intervention is effective, but the added value of the booster sessions is uncertain.     

Insensitivity of the human sentence-processing system to hierarchical structure

Although it is generally accepted that hierarchical phrase structures are instrumental in describing human language, their role in cognitive processing is still debated. We investigated the role of hierarchical structure in sentence processing by implementing a range of probabilistic language models, some of which depended on hierarchical structure, and others of which relied on sequential structure only. All models estimated the occurrence probabilities of syntactic categories in sentences for which reading-time data were available. Relating the models' probability estimates to the data showed that the hierarchical-structure models did not account for variance in reading times over and above the amount of variance accounted for by all of the sequential-structure models. This suggests that a sentence's hierarchical structure, unlike many other sources of information, does not noticeably affect the generation of expectations about upcoming words.