Irritability and rejection-elicited aggression in adolescents and young adults

Violence exacts staggering personal and financial costs - a burden disproportionally born by adolescents and young adults. This may be partially due to an increased sensitivity to social rejection during this critical phase of development. Irritability, a transdiagnostic symptom, is often elicited by social interactions. Yet, little is known about age differences in social rejection-elicited aggression and irritability. Progress toward testing such relations has been hindered by a lack of ecologically-valid tasks that enable the measurement of in-the-moment social rejection-elicited aggression.

In this paper, we describe an initial study of young adults (n = 55) that demonstrates the efficacy of a novel Virtual School and Aggression Paradigm (VS-AP). Next, we replicate these results in a second study of adolescents and young adults (ages 11-25 years; n = 173) and examine relations between social rejection-elicited aggression, irritability, and age.

We found that aggressive behavior in the VS-AP differed for accepting, rejecting, and unpredictable peer types (Study 1: F(2, 108) = 20.57, p < .001, ε²  = .28; Study 2: F(2, 344) = 152.13, p < .001, ε²  = .47), demonstrating that the VS-AP successfully models social rejection-elicited aggression. In Study 2, age was negatively correlated with aggressive behavior (r = -.29, p < .001) and irritability (r = -.28, p < .001), while irritability was positively correlated with aggressive behavior (r = .28, p < .001). Age moderated the relation between social rejection-elicited aggression and irritability. Specifically, irritability was more predictive of aggression in young adults than in adolescents (F(3, 167) = 7.07, p < .001).

Data suggest mechanisms promoting rejection-elicited aggression may differ across development and vary for those with and without high levels of irritability. The VS-AP is a promising tool for probing neurocognitive, developmental, and clinically relevant mechanisms underlying social rejection-elicited aggression.