To test specific hypotheses about the relation between hostile intent attribution (HIA) and children’s aggressive behavior, a multilevel meta‐analysis was conducted on 111 studies with 219 effect sizes and 29.272 participants. A positive association between HIA and aggression was found, but effect sizes varied widely between studies. Results suggested that HIA is a general disposition guiding behavior across a broad variety of contexts, whereas the strength of the relation between HIA and aggression depends on the level of emotional engagement. The relation is stronger for more reliable HIA measures, but is not stronger for reactive aggression or co‐morbid attention‐deficit hyperactivity disorder than for aggression in general. The importance of understanding specific moderators of effect size for theory development is discussed.

Interventions for children's aggression typically target assumed underlying mechanisms, such as anger regulation and hostile intent attribution. The expectation here is that targeting these mechanisms will result in within-person changes in aggression. However, evidence for these mechanisms is mostly based on between-person analyses. We, therefore, examined whether within-person changes in adaptive anger regulation and hostile intent attribution covaried with within-person changes in children's aggression.Children (N = 223; age 7-12; 46% boys) filled out four weekly report measures to assess adaptive anger regulation, hostile intent attribution, and aggression. The psychometric properties of these novel measures were adequate. Results of multi-level analyses revealed within-person effects: weekly changes in adaptive anger regulation and hostile intent attribution covaried with changes in children's aggression. This corresponded with between-person findings on the same data: children with lower levels of adaptive anger regulation and higher levels of hostile intent attribution reported more aggression than other children. These findings support the idea that targeting anger regulation and hostile intent attribution in interventions may lead to changes in individual children's aggression.

Evidence-based cognitive behavioral therapies (CBTs) for children with aggressive behavior problems have only modest effects. Research is needed into new methods to enhance CBT effectiveness. The aims of the present study were to (1) examine whether interactive virtual reality is a feasible treatment method for children with aggressive behavior problems; (2) investigate children’s appreciation of the method; and (3) explore whether children’s aggression decreased during the ten-session treatment. Six boys (8–12 years) participated at two clinical centers in the Netherlands. Newly developed weekly reports were collected on treatment feasibility (therapist-report), treatment appreciation (child report), and children’s aggression (child/parent report). Results supported treatment feasibility: therapists delivered on average 98% of the session content, provided more than the recommended practice time in virtual reality, experienced few technical issues, and were satisfied with their treatment delivery. Children highly appreciated the treatment. Parents reported decreases in children’s aggression over the treatment period (i.e., between week 1 and week 10), but children did not. The promising findings of this feasibility study warrant randomized controlled trials to determine whether interactive virtual reality enhances CBT effectiveness for children with aggressive behavior problems.

This multicenter randomized controlled trial investigated whether interactive virtual reality enhanced effectiveness of Cognitive Behavioral Therapy (CBT) to reduce children's aggressive behavior problems. Boys with aggressive behavior problems (N = 115; Mage = 10.58, SD = 1.48; 95.7% born in Netherlands) were randomized into three groups: CBT with virtual reality, CBT with roleplays, or care‐as‐usual. Bayesian analyses showed that CBT with virtual reality more likely reduced aggressive behavior compared to care‐as‐usual for six of seven outcomes (ds 0.19–0.95), and compared to CBT with roleplays for four outcomes (ds 0.14–0.68). Moreover, compared to roleplays, virtual reality more likely enhanced children's emotional engagement, practice immersion, and treatment appreciation. Thus, virtual reality may be a promising tool to enhance CBT effectiveness for children with aggressive behavior problems.