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.     

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.     

The contribution of “cool” and “hot” components of decision-making in adolescence: Implications for developmental psychopathology

Impairments in either “cool” or “hot” processes may represent two pathways to deficient decision-making. Whereas cool processes are associated with cognitive and rational decisions, hot processes are associated with emotional, affective, and visceral processes. In this study, 168 boys were administered a card-playing task at ages 13 and 14 years to assess response perseveration. This task was designed to initially reward playing and gradually associate playing with punishment. Measures of subjective ordering (cool processes) and neuroticism (hot processes) at age 13 years were used to examine how these individual characteristics relate to perseveration over time. A decrease in perseveration from age 13 to 14 was associated with cool processes whereas hot processes were associated with response perseveration only over time. A complementary but simultaneous assessment of cool and hot processes, such as neuropsychological and personality tests, could facilitate treatment planning of children with behavioral problems.     

Did the instigator intend to provoke? A key moderator in the relation between trait aggression and aggressive behavior

The purpose of this study was to investigate the cross‐situational consistency of trait aggression in provoking situations where an instigator (1) clearly intended to provoke, (2) clearly intended not to provoke, or (3) where presence of intention was ambiguous. It was hypothesized that cross‐situational consistency would be substantial, and that trait aggression would have the greatest impact on aggressive behavior in ambiguous situations. Participants were 80 female and 38 male undergraduate students. They completed the Aggression Questionnaire [Buss and Perry, J Pers Soc Psychol, 1992, pp. 452], read a set of 24 vignettes depicting conflict situations and rated their perceived likelihood of becoming angry and aggressive in those situations. An overall cross‐situational consistency correlation coefficient of r=.47 was found. It was also found that trait aggression had a significantly greater effect on the likelihood of aggressive responses in the ambiguous and intentional situations than it did in the unintentional situations. These results are discussed in relation to trait activation and hostile attribution bias. Aggr. Behav. 30:409–424, 2004. © 2004 Wiley‐Liss, Inc.     

Expressive language and prosocial behaviour in early childhood: Longitudinal associations in the UK Millennium Cohort Study

Background: Early childhood is a crucial period for language development and building social skills. While distinct, these two processes may impact upon each other.

Aims: The current study aimed to identify the directional associations between expressive language ability and prosocial behaviour between three and five years of age.

Methods: Participants included 14, 004 children and their families enrolled in the UK Millennium Cohort Study. Children’s expressive language and prosocial behaviour were assessed at three and five years of age utilizing standardized assessments and parent reports. Cross-lagged models were used for data analysis.

Results: Better expressive language at three years was associated with increased prosocial behaviour by five years. No support for the inverse direction of association was found.

Conclusions: Children’s early ability to effectively express themselves with others may help in building better social relationships by entry into formal schooling. Programming efforts that are tailored towards enhancing positive behavioural growth and social skills in the toddler years are likely to be effective when expressive language is also a targeted component of the toddler’s skill development.     

The Effectiveness of Parenting Programs for Incarcerated Mothers: A Systematic Review

There is evidence to suggest that maternal incarceration can have negative implications for children. Children in these families can be at greater risk for conduct problems and antisocial behavior, as well as school dropout and academic failure. Institution-based parenting programs represent one means of addressing the potential negative impacts of maternal incarceration on children’s wellbeing. Through parent training programs, mothers may develop skills and strategies to help their children cope with the challenges and stressors associated with incarceration. However, it is currently unclear whether parenting programs for mothers in these facilities have a positive effect on different parenting outcomes. We conducted a systematic search of several electronic databases using key search terms and identified sixteen treatment studies. The results suggest that in the short-term, corrections-based parenting programs are associated with positive effects on parenting behavior, parenting attitudes, and parenting knowledge. However, these programs appear to have no effect on parenting stress immediately post-treatment. Implications for practice and recommendations for future research are discussed.     

Eye movements may cause motor contagion effects

When a person executes a movement, the movement is more errorful while observing another person’s actions that are incongruent rather than congruent with the executed action. This effect is known as “motor contagion”. Accounts of this effect are often grounded in simulation mechanisms: increased movement error emerges because the motor codes associated with observed actions compete with motor codes of the goal action. It is also possible, however, that the increased movement error is linked to eye movements that are executed simultaneously with the hand movement because oculomotor and manual-motor systems are highly interconnected. In the present study, participants performed a motor contagion task in which they executed horizontal arm movements while observing a model making either vertical (incongruent) or horizontal (congruent) movements under three conditions: no instruction, maintain central fixation, or track the model’s hand with the eyes. A significant motor contagion-like effect was only found in the ‘track’ condition. Thus, ‘motor contagion’ in the present task may be an artifact of simultaneously executed incongruent eye movements. These data are discussed in the context of stimulation and associative learning theories, and raise eye movements as a critical methodological consideration for future work on motor contagion.