Taming anger and trusting others: Roles of skin conductance, anger regulation, and trust in children's aggression

Inhibitory Control in Early Childhood Aggression Subtypes: Mediation by Irritability

The present study tested irritability as a mediator of inhibitory control's (IC) associations with crossed form and function aggression subtypes over one year in early childhood (N = 300, M_age = 44.70 months, SD = 4.38 months). We hypothesized lower IC would predict increases in irritability, which would in turn predict increases in aggression overall (severity) and a predominance of reactive over proactive subtypes (directionality), and considered moderation by gender. Irritability mediated IC's relations in the predicted direction for physical severity for girls only and relational severity for both genders. Lower IC predicted increases in irritability, which in turn predicted increasing predominance of reactive over proactive physical and relational aggression. The predicted indirect effect was significant for physical but not relational directionality. Findings highlight the viability of directionality scores for disentangling these effects, and that developmental associations between IC, irritability, and reactive functions of aggression are evident in early childhood.

Reactive vs proactive aggression: A differential psychobiological profile? Conclusions derived from a systematic review

INTRODUCTION

Scholars have established subcategories of aggressive behavior in order to better understand this construct. Specifically, a classification based on motivational underpinnings makes it possible to differentiate between reactive and proactive aggression. Whereas reactive aggression is characterized by emotional lability, which means it is prone to impulsive reactions after provocation, proactive aggression is driven by low emotionality and high levels of instrumentality to obtain benefits. Some authors have conceived these two types as having a dichotomous nature, but others argue against this conceptualization, considering a complementary model more suitable. Hence, neuroscientific research might help to clarify discussions about their nature because biological markers do not present the same biases as psychological instruments.

AIM

The main objective of this study was to carry out a systematic review of studies that assess underlying biological markers (e.g., genes, brain, psychophysiological, and hormonal) of reactive and proactive aggression.

METHODS

To carry out this review, we followed PRISMA quality criteria for reviews, using five digital databases complemented by hand-searching.

RESULTS

The reading of 3993 abstracts led to the final inclusion of 157 papers that met all the inclusion criteria. The studies included allow us to conclude that heritability accounted for approximately 45% of the explained variance in both types of aggression, with 60% shared by both, especially, for overt and physical expression forms, and 10% specific to each type. Regarding allelic risk factors, whereas low functioning variants affecting serotonin transport and monoaminoxidase increased the risk of reactive aggression, high functioning variants were associated with proactive aggression. Furthermore, brain analysis revealed an overlap between the two types of aggression and alterations in the volume of the amygdala and temporal cortex. Moreover, high activation of the medial prefrontal cortex (PFC) facilitated proneness to both types of aggression equally. Whereas stimulation of the right ventrolateral (VLPFC) and dorsolateral (DLPFC) reduced proneness to aggression, inhibition of the left DLPFC increased it. Finally, psychophysiological and hormonal correlates in general did not clearly differentiate between the two types because they were equally related to each type (e.g., low basal cortisol and vagal variability in response to acute stress) CONCLUSIONS: This study reinforces the complementary model of both types of aggression instead of a dichotomous model. Additionally, this review also offers background about several treatments (i.e., pharmacological, non-invasive brain techniques…) to reduce aggression proneness.

The development of forms and functions of aggression during early childhood: A temperament-based approach

This study used a short-term longitudinal design with theoretically derived preregistered hypotheses and analyses to examine the role of temperament in the development of forms (i.e., physical and relational) and functions (i.e., proactive and reactive) of aggressive behavior in early childhood (N = 300, M age = 44.70 months, SD = 4.38, 44% girls). Temperament was measured via behavioral reports of emotional dysregulation, fearlessness/daring, and rule internalization/empathy and, in a subsample that completed a physiological assessment, via skin conductance and respiratory sinus arrhythmia. Emotion dysregulation generally served as a risk factor for all subtypes of aggression, with evidence of stronger associations with reactive as compared to proactive functions of relational aggression for girls. Daring predicted increases in physical aggression, especially among boys, and rule internalization predicted decreases in relational aggression, especially among girls. Rule internalization mediated longitudinal associations between daring and proactive relational aggression for girls. Some evidence also emerged supporting associations between adaptive functioning (i.e., high empathy, high respiratory sinus arrhythmia) and proactive functions of aggression. Findings highlight distinct temperamental risk factors for physical versus relational aggression and provide partial support for gender-linked theories of the development of aggression.

Trust, Forgiveness, and Peace: The Influence of Adolescent Social Identity in a Setting of Intergroup Conflict

Following the signing of peace agreements, post-accord societies often remain deeply divided across group lines. There is a need to identify antecedents of youth's support for peace and establish more constructive intergroup relations. This article explored the effect of out-group trust, intergroup forgiveness and social identity on support for the peace process among youth from the historic majority and minorities communities in Belfast, Northern Ireland. The sample comprised of 667 adolescents (49% male; M=15.74, SD=1.99 years old) across two time points. Results from the structural equation model suggested that out-group trust was related to intergroup forgiveness over time, while forgiveness related to later support for the peace process. Strength of in-group social identity differentially moderated how out-group trust and intergroup forgiveness relate to later support for peace among youth from the conflict-related groups (i.e., Protestants and Catholics). Implications for consolidating peace in Northern Ireland are discussed, which may be relevant to other settings affected by intergroup conflict.

Kindhearted: Ethical guilt and ethical heart rate reactivity codevelop with aggression across childhood

Largely cross-sectional evidence indicates that ethical guilt is a robust predictor of childhood aggression. However, the underlying mechanisms of ethical guilt-in part assessed as ethical heart rate (HR) reactivity in the present study-are less clear, and longitudinal associations between ethical guilt, its underlying mechanisms, and aggression have not been explored. The present study used a multicohort longitudinal design to assess these constructs across early and middle childhood. At the beginning of the study and 2 years later, cohorts of 4- and 8-year-olds (ns = 150; N = 300) reported their guilt in response to an ethical transgression (i.e., pushing) and a nonethical transgression (i.e., breaking a classroom rule), and their HR was measured while they imagined committing these acts. Caregivers reported their child's aggression at each time point via questionnaire. Latent difference score models indicated that, regardless of cohort, children who increased in their ability to prioritize ethical guilt over 2 years were more likely to decrease in aggression over the same period. Moreover, children whose HR reactivity became more sensitive to ethical transgressions over time showed corresponding declines in aggression over time. Overall, these findings highlight the potential protective roles of children's capacities to react affectively and autonomically to the gravity of ethical transgressions across early and middle childhood.