Social judgments, frontal asymmetry, and aggressive behavior in young children: A replication study using EEG.

Early in their lives young children are confronted with social judgments by peers. Previous studies have shown that in adults negative social judgments are associated with more aggressive behavior. However, little is known about the relation between social judgments and aggressive behavior, or the underlying neurocognitive mechanisms, in early childhood. We developed the Social Network Aggression Task - Early Childhood (SNAT-EC) to examine the mediating role of frontal EEG asymmetry in the relation between social judgment and aggressive behavior in 4-6 year old children. To replicate our findings, we included three samples: a pilot sample, test sample 1 and test sample 2 (total N = 78). In the SNAT-EC, children receive positive, negative and neutral social judgments about their chosen cuddly animal by same-aged unfamiliar peers. EEG was acquired to measure frontal asymmetry during the processing of social judgments. Aggressive behavior was measured as the duration of a button press with which children could destroy balloons of the judging peer, thus reducing the number of remaining balloons for that peer. We used a within-subject mediation model to test whether frontal asymmetry mediated the effect of social judgment (negative vs. positive) on aggressive behavior. Results show that the SNAT-EC robustly elicits more aggressive behavior in response to negative social judgments about the cuddly animal compared to positive judgments. Meta-analysis revealed a large combined effect size (r = .42) for the relation between negative (vs. positive) social judgments and aggressive behavior. However, frontal asymmetry in response to the social judgments did not mediate the relation between social judgment and aggressive behavior. Future studies should search for other neural mediators to bridge the brain-behavior gap between social judgments and aggressive behavior, in particular in early childhood.