Age differences in the prevalence of physical aggression among 5-11-year-old Canadian boys and girls

It has been proven extremely difficult in the past to estimate the prevalence of physical aggression in children for two main reasons: (a) a heterogeneous sampling of behaviors (i.e., mix between physically aggressive and non-physically aggressive antisocial behaviors), and (b) a lack of a "gold standard" to identify children who exhibit physically aggressive behaviors on a frequent basis. The goal of this study was to test for age differences in the prevalence of physical aggression in the Canadian population of school-aged boys and girls, using cross-sectional data from the National Longitudinal Survey of Children and Youth (NLSCY). The first wave of the NLSCY included a representative sample of 12,292 Canadian children aged 5-11 years. We used latent class analysis to identify children whose propensity to exhibit physically aggressive behaviors was much higher than that of other children of the same age and sex in the population. The prevalence of physical aggression was estimated at 3.7% in 5-11-year-old boys and ranged from .5% to 2.3% in 11 and 5-year-old girls, respectively. Hence, the results show a decreasing trend in the prevalence of physical aggression with age for girls, but not for boys. These findings suggest the importance of considering the developmental pathways of physical aggression for boys and girls separately.     

Rats take correct novel routes and shortcuts in an enclosed maze

In 3 experiments, rats were allowed to travel selected routes along the internal alleys of a cross-maze that led from one distinctive end box to another. The maze and procedures used were designed to control the rats' ability to use intrinsic and extrinsic cues to their location in the maze; thus, only the internal geometry of the maze could be learned and used to travel between one end box and another. After an initial exploration phase, rats were given novel routes and shortcut tests that involved peripheral alleys not before traveled. Rats chose the correct novel path or shortcut significantly above chance on some tests in Experiments 1 and 2 and significantly better than a control group in Experiment 3. The findings suggest that rats were able to compute novel routes and shortcuts within the maze on the basis of limited experience with the internal geometry of the maze.     

Developmental coordination disorder pertains to a deficit in perceptuo-motor synchronization independent of attentional capacities

We investigated from a dynamic pattern perspective to motor coordination whether the deficiency in motor coordination characterizing Developmental Coordination Disorder children pertains to a general disorder in synchronization leading to a lower stability of the performed coordination pattern, and the extent to which the trouble is linked to attentional capacities. Twenty-four DCD children without ADHD aged eight to thirteen and 60 control children were asked (1) to perform a Continuous Performance Test assessing sustained attention; (2) to flex one finger either in synchrony or in syncopation with a visual periodic signal whose frequency was increased stepwise, assessing synchronization abilities. For the attentional task, percentage of exact responses, number of errors and reaction time were recorded. For the synchronization task, we measured relative phase (i.e., the ratio between the stimulus and the response onset and the time separating two successive stimuli). DCD children were significantly more variable than controls in both conditions and the difficulty in synchronization was unrelated to attentional disorders (ANCOVA). These findings support the idea of a general synchronization disorder in DCD children underlying their poor motor coordination. Moreover, this synchronization disorder does not appear to be strictly dependent on the level of sustained attentional capacities.     

Reproducibility of distance and direction errors associated with forward, backward, and sideway walking in the context of blind navigation

The ability to navigate without vision towards a previously seen target has been extensively studied, but its reliability over time has yet to be established. Our aims were to determine distance and direction errors made during blind navigation across four different directions involving three different gait patterns (stepping forward, stepping sideway, and stepping backward), and to establish the test-retest reproducibility of these errors. Twenty young healthy adults participated in two testing sessions separated by 7 days. They were shown targets located, respectively, 8 m ahead, 8 m behind, and 8 m to their right and left. With vision occluded by opaque goggles, they walked forward (target ahead), backward (target behind), and sideway (right and left targets) until they perceived to be on the target. Subjects were not provided with feedback about their performance. Walked distance, angular deviation, and body rotation were measured. The mean estimated distance error was similar across the four walking directions and ranged from 16 to 80 cm with respect to the 8 m target. In contrast, direction errors were significantly larger during sideway navigation (walking in the frontal plane: leftward, 10 degrees +/- 15 degrees deviation; rightward, 18 degrees +/- 13 degrees) than during forward and backward navigation (walking in the sagittal plane). In general, distance and direction errors were only moderately reproducible between the two sessions [intraclass correlation coefficients (ICCs) ranging from 0.682 to 0.705]. Among the four directions, rightward navigation showed the best reproducibility with ICCs ranging from 0.607 to 0.726, and backward navigation had the worst reliability with ICCs ranging from 0.094 to 0.554. These findings indicate that errors associated with blind navigation across different walking directions and involving different gait patterns are only moderately to poorly reproducible on repeated testing, especially for walking backward. The biomechanical constraints and increased cognitive loading imposed by changing the walking pattern to backward stepping may underlie the poor performance in this direction.     

Working memory and error detection in texts: what are the roles of the central executive and the phonological loop?

Subjects performed a text error detection task, either alone or in conjunction with a secondary task aimed at specifically hindering the functioning of either the central executive in working memory or of the phonological loop. We focused on the decline in detection performance as a function of the type of error to be detected (typographical, orthographic, or semantic/syntactic) and the processing span required for detection (one word, several words within the same clause, or several clauses). The results showed that the central executive in working memory is involved in detecting semantic/syntactic errors and in detecting orthographic ones, but not in detecting typographical errors. Moreover, the degree of involvement increases with the processing span. The phonological loop is involved in detection whenever processing above the word level is required. As observed in many studies, these results suggest that the difficulty subjects have detecting semantic errors as compared to other types of errors is due to the heavier working memory load: maintenance of the phonological representation and greater involvement of the central executive. © 1998 John Wiley & Sons, Ltd.     

A Dual Route in Explaining Health Outcomes in Natural Disaster1

Human beings seem to be resilient and have a great capacity to overcome adverse circumstances. One apparent variable that may predict people's emotional and physical health after a trauma is their general level of psychological well‐being ( McMillen, Smith, & Fisher, 1997 ). The current study explores the role of subjective vitality and the perception of stress as mediators between general life satisfaction and post‐trauma physiological and psychological health related to the Canadian 1998 Ice Storm. Results of this dual route indicate that satisfaction with life positively predicted subjective vitality and negatively predicted perceived stress. In turn, subjective vitality lead to lower levels of ill‐health, whereas perception of stress lead to higher levels of physical symptoms and depression.     

Interrelations between maternal smoking during pregnancy,birth weight and sociodemographic factors in the prediction of early cognitive abilities

Maternal prenatal smoking, birth weight and sociodemographic factors were investigated in relation to cognitive abilities of 1544 children (aged 3.5 years) participating in the Québec Longitudinal Study of Children's Development. The Peabody Picture Vocabulary Test (PPVT) was used to assess verbal ability, the Wechsler Preschool and Primary Scale of Intelligence‐Revised (WPPSI‐R) block design test to assess visuospatial ability, and the Visually Cued Recall (VCR) task to assess short‐term memory. Prenatal smoking was related to performance on the WPPSI‐R, the PPVT, and the VCR, although it did not independently predict any cognitive ability after maternal education was taken into account. Birth weight was a more robust predictor of all outcome measures and independently predicted VCR‐performance. Birth weight interacted significantly with family income and maternal education in predicting visuospatial ability, indicating a greater influence of birth weight under relatively poor socio‐economic conditions. Parenting and family functioning mediated associations between maternal education/family income and cognitive task performance under different birth weight conditions, although there were indications for stronger effects under relatively low birth weight. We conclude that investigations of moderating and mediating effects can provide insights into which children are most at risk of cognitive impairment and might benefit most from interventions. Copyright © 2006 John Wiley & Sons, Ltd.     

Testing the developmental distinctiveness of male proactive and reactive aggression with a nested longitudinal experimental intervention

An experimental preventive intervention nested into a longitudinal study was used to test the developmental distinctiveness of proactive and reactive aggression. The randomized multimodal preventive intervention targeted a subsample of boys rated disruptive by their teachers. These boys were initially part of a sample of 895 boys, followed from kindergarten to 17 years of age. Semiparametric analyses of developmental trajectories for self‐reported proactive and reactive aggression (between 13 and 17 years of age) indicated three trajectories for each type of aggression that varied in size and shape (Low, Moderate, and High Peaking). Intent‐to‐treat comparisons between the boys in the prevention group and the control group confirmed that the preventive intervention between 7 and 9 years of age, which included parenting skills and social skills training, could impact the development of reactive more than proactive aggression. The intervention effect identified in reactive aggression was related to a reduction in self‐reported coercive parenting. The importance of these results for the distinction between subtypes of aggressive behaviors and the value of longitudinal‐experimental studies from early childhood onward is discussed. Aggr. Behav. 36:127–140, 2010. © 2010 Wiley‐Liss, Inc.     

A new look at the attribution of moral responsibility: The underestimated relevance of social roles

What are the main features that influence our attribution of moral responsibility? It is widely accepted that there are various factors which strongly influence our moral judgments, such as the agent’s intentions, the consequences of the action, the causal involvement of the agent, and the agent’s freedom and ability to do otherwise. In this paper, we argue that this picture is incomplete: We argue that social roles are an additional key factor that is radically underestimated in the extant literature. We will present an experiment to support this claim.