From response-set to prediction hypotheses: Rule acquisition among preschoolers and second graders

It was proposed that prediction hypotheses do not emerge full blown in the repertoire of the young child. Instead, the component units out of which predictions are consolidated (win-stay, lose-shift) are acquired independently and at different rates. The young child's behavior is at first dominated by response sets in which the win and lose components involve the same action (win-stay, lose-stay or win-shift, lose-shift). The components of response sets must be separated and coordinated with task-relevant information before appropriate components are consolidated to yield prediction hypotheses. A combination of learning-set and blank-trial procedures was used to evaluate this conception with preschoolers (mean CA = 4:1) and second graders (mean CA = 7:6). Results revealed that children of both age levels exhibited response patterns that corresponded to hypotheses in most of their probes (.89 to. 98). The striking finding was the relative weakness of win-stay on object cues at the outset of acquisition, particularly among the younger children. In contrast. lose-shift object was strong from the outset among children of both age levels. Once the two components (win-stay object, lose-shift object) were consolidated, the resulting scheme was durable, in that transfer to more complex problems was nearly perfect. Children who did not achieve criterion (in 70 problems) failed because they exhibited mostly position hypotheses and/or because the strength of win-stay object remained weak throughout all sessions.     

Beyond the reactive‐proactive dichotomy: Rage,revenge, reward,and recreational aggression predict early high school bully and bully/victim status

The role of reactive and proactive aggression in school bullying perpetration remains unclear. In this study, we explore the predictive value of an expanded model of aggression motives based on the Quadripartite Violence Typology (QVT), which distinguishes between motivational valence (appetitive or aversive) and recruitment of deliberative self‐control to derive four classes of motives: Rage, Revenge, Reward, and Recreation. With a sample of 1,802 students from grades 7–9, we assessed aggression motives via self‐report, along with self‐report of bullying perpetration and victimization, which were used to assign students into categories of Pure Bully, Bully/Victim (B/V), Pure Victim, and Uninvolved. Two structural models were computed to examine the relationship between these four categories of bullying involvement and aggression motives, using conservative and liberal bullying cutoffs. As predicted, B/V status was more strongly related to Rage and Revenge motives. However, B/Vs had higher scores than Pure Bullies for almost all aggression motives, including Recreation. We discuss the implications of addressing Revenge and Recreation, as well as Reward and Rage (which map most clearly to proactive and reactive aggression, respectively) aggression motives, for bullying prevention and intervention strategies, especially among adolescents for whom extant bullying prevention strategies may be ineffective or counterproductive.

     

Using mu rhythm desynchronization to measure mirror neuron activity in infants

The Mirror Neuron System hypothesis stating that observed actions are projected onto the observer’s own action system assigns an important role to development, because only actions mastered by the observer can be mirrored. The purpose of the present study was to investigate whether there is evidence of a functioning mirror neuron system (MNS) in 8-month-old infants. High-density EEG was used to assess the mu rhythm desynchronization in an action observation task where the infants observed a live model. To reduce noise, ICA decompositions were used. The results show a higher desynchronization of the mu rhythm when infants observed a goal-directed action than when they observed a spatially similar non-goal-directed movement. The localizations of the sources are in agreement with those proposed by the MNS hypothesis. This indicates that the MNS is functioning at this age.     

Timely Completion of Class Requirements: Effects of Student and Faculty Gender

Male and female students have displayed different reactions to the gender of their faculty. This research was designed to explore whether biases exist early in the school term. Students unfavorable attitudes toward instructors were measured by the extent to which they delayed completing a course requirement: participation in a subject pool. Students scheduled a date upon which to participate in a research study. Discrepancies between their scheduled and their actual participation dates reveal that male students delayed their requirement (a) more when their instructors were female than when they were male, and (b) more than female students when the instructors were female. Supporting data suggest that the delayed completion time reflects lower evaluations of female faculty. Discussion focuses on implications in academic settings.     

The power of statistical tests for moderators in meta-analysis

Calculation of the statistical power of statistical tests is important in planning and interpreting the results of research studies, including meta-analyses. It is particularly important in moderator analyses in meta-analysis, which are often used as sensitivity analyses to rule out moderator effects but also may have low statistical power. This article describes how to compute statistical power of both fixed- and mixed-effects moderator tests in meta-analysis that are analogous to the analysis of variance and multiple regression analysis for effect sizes. It also shows how to compute power of tests for goodness of fit associated with these models. Examples from a published meta-analysis demonstrate that power of moderator tests and goodness-of-fit tests is not always high.