Examining genetic and environmental effects on reactive versus proactive aggression

This study compared the contribution of genes and environment to teacher-rated reactive and proactive aggression in 6-year-old twin pairs (172 pairs: 55 monozygotic girls, 48 monozygotic boys, 33 dizygotic girls, 36 dizygotic boys). Genetic effects accounted for 39% of the variance of reactive aggression and for 41% of the variance of proactive aggression. The remainder of the variance was explained by unique environmental effects. Genetic as well as unique environmental effects were significantly correlated across reactive and proactive aggression (genetic correlation = .87, environmental correlation = .34), but this overlap was largely due to a common underlying form of aggression (i.e., teacher-rated physical aggression). Once common etiological factors due to physical aggression were accounted for, reactive and proactive aggression shared no other genes and only a few environmental influences, although additional specific genetic and environmental effects were observed for both reactive and proactive aggression. These specific effects indicate that both reactive and proactive aggression may be influenced mostly by socialization experiences that are specific to each type of aggression and only to a very small degree by specific genes.     

Do Early Difficult Temperament and Harsh Parenting Differentially Predict Reactive and Proactive Aggression?

The goal of this study was to examine the links between difficult temperament (i.e., negative emotionality) and harsh parental discipline during toddlerhood, and reactive and proactive aggression in kindergarten. These links were assessed on a longitudinal population-based study of 1516 boys and girls followed longitudinally from the age of 17 months through the age of 72 months. Two possible models were tested to examine the interplay between negative emotionality and harsh parenting in predicting later reactive aggression compared to proactive aggression. The first was an additive model where both aspects make unique contributions in predicting later reactive aggression. The second model was an interactive model where harsh parenting exacerbates the link between negative emotionality and reactive aggression. Results showed a specific contribution of negative emotionality to reactive aggression. The results relative to harsh parenting are more mixed but nonetheless in line with developmental models stressing different pathways to reactive and proactive aggression.     

On the role of item similarity in retrieval-induced forgetting

We report on two experiments designed to examine how the similarity of retrieval-practised and not-retrieval-practised items influences the amount of retrieval-induced forgetting. Participants studied categorised item lists with each category consisting of exemplars from two different semantic subcategories. Using both the retrieval practice paradigm (Experiment 1) and the output interference paradigm (Experiment 2) we found that the retrieval of a subset of the studied items impaired the subsequent recall of the nonpractised items if the two types of items were fairly dissimilar to each other (same category but different subcategory) but did not induce impairment if the two types of items were highly similar (same category and subcategory). These results indicate that a high degree of similarity of practised and nonpractised items can eliminate retrieval-induced forgetting. They also suggest that forgetting in the retrieval practice paradigm and forgetting in the output interference paradigm are mediated by the same mechanisms. The relation of the present results to other very recent findings about the role of item similarity in retrieval-induced forgetting in discussed.     

Developmental profiles of peer social preference over the course of elementary school: associations with trajectories of externalizing and internalizing behavior

Using a new longitudinal clustering technique, this study aimed to (a) empirically identify groups of children with distinct longitudinal profiles of peer social preference during elementary school; (b) compare these groups regarding their longitudinal pattern of classification into J. D. Coie, K. A. Dodge, and H. Coppotelli's (CDC; 1982) sociometric categories; and (c) compare these groups regarding their longitudinal trajectories of antisocial, hyperactive, and anxious behavior. Based on 299 children, 3 groups were identified: a stable popular group, a stable average group, and an unpopular group whose social preference decreased over time. Each of the groups showed considerable overlap over time with their closest corresponding CDC category (popular, average, rejected). Growth curve analyses showed that externalizing and internalizing behavior generally decreased over time, but overall means and the rates of decrease differed in the 3 groups.     

Influence of Deviant Friends on Delinquency: Searching for Moderator Variables

Three categories of potential moderators of the link between best friend's deviancy and boys' delinquency during early adolescence were investigated: personal (i.e., disruptiveneness profile during childhood, attitude toward delinquency), familial (i.e., parental monitoring, attachment to parents), and social (i.e., characteristics of other friends). Best friend's and other friends' deviancy were assessed during preadolescence through the use of peer ratings. Potential moderators were assessed at the same age period with teacher ratings or self-reports. Finally, delinquent behaviors were assessed at ages 13 and 14, as well as age 10 for control purposes, with self-reports. Results showed that boys' disruptiveness profiles during childhood, attachment to parents, and attitude toward delinquency moderated the link between best friend's deviancy and later delinquent behaviors. Other friends' deviancy and parental monitoring had main effects but no moderating effects. These results help clarify the conditions under which exposure to a deviant best friend can influence boys' delinquent behaviors. They also help to reconcile different theoretical explanations of the role of deviant friends in the development of delinquency.     

Reversing the testing effect by feedback: Behavioral and electrophysiological evidence

The testing effect refers to the finding that retrieval practice of previously studied information enhances its long-term retention more than restudy practice does. Recent work showed that the testing effect can be dramatically reversed when feedback is provided to participants during final recall testing (Storm, Friedman, Murayama, & Bjork, 2014). Following this prior work, in this study, we examined the reversal of the testing effect by investigating oscillatory brain activity during final recall testing. Twenty-six healthy participants learned cue–target word pairs and underwent a practice phase in which half of the items were retrieval practiced and half were restudy practiced. Two days later, two cued recall tests were administered, and immediate feedback was provided to participants in Test 1. Behavioral results replicated the prior work by showing a testing effect in Test 1, but a reversed testing effect in Test 2. Extending the prior work, EEG results revealed a feedback-related effect in alpha/lower-beta and retrieval-related effects in slow and fast theta power, with practice condition modulating the fast theta power effect for items that were not recalled in Test 1. The results indicate that the reversed testing effect can arise without differential strengthening of restudied and retrieval-practiced items via feedback learning. Theoretical implications of the findings, in particular with respect to the distribution-based bifurcation model of testing effects (Kornell, Bjork, & Garcia, 2011), are discussed.     

The “New Big Five” from a personalistic point of view

McAdams and Pals (2006) “New Big Five” principles are contrasted with William Stern's conception of the person. It is criticized that the intra-individual organization of the person is not adequately addressed in the “New Big Five” approach: McAdams and Pals are shifting the issue of the idiosyncratic organization of the person to the level of a more or less coherent life narrative. The person tells or constructs a narrative, the person, however, is not the narrative.It is therefore suggested to complement and enrich the “New Big Five” with the three primary characteristics of the person as proposed by William Stern: unitas multiplex, purposefulness and individuality. In addition, Stern's concept of introception is suggested as a more integrated view of how the external world is internalized within the person. In concluding, the significance of Stern's critical personalism for an integrative science of personality in the 21^st century is highlighted.     

Theta oscillations predict the detrimental effects of memory retrieval

Retrieving a target item from episodic memory typically enhances later memory for the retrieved item but causes forgetting of competing irrelevant memories. This finding is termed retrieval-induced forgetting (RIF) and is assumed to be the consequence of an inhibitory mechanism resolving retrieval competition. In the present study, we examined brain oscillatory processes related to RIF, as induced by competitive memory retrieval. Contrasting a competitive with a noncompetitive retrieval condition, we found a stronger increase in early evoked theta (4–7 Hz) activity, which specifically predicted RIF, but not retrieval-induced enhancement. Within the cognitive framework of RIF, these findings suggest that theta oscillations reflect arising interference and its resolution during competitive retrieval in episodic memory. Supplemental materials for this article may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.