Exploring the Relationship Between Childhood Irritability and Aggression Across Development

Courtney Kaplan, BA

McLean Hospital – Research Assistant

Scientific Abstract

Background: Irritability, a mood resulting from blocked goal attainment, and aggression, often seen as the behavior resulting from these feelings, are two of the most common reasons for childhood mental health consults. Despite their distinct characteristics, irritability and aggression are often conflated to describe youth who are difficult to manage, and few studies have clearly investigated their relationship. We aimed to explore this relationship and the associations of irritability and aggression with age. We hypothesize that irritability will be a significant predictor of aggression over and above age and biological sex. Furthermore, we predict that aggression and irritability may decrease with age.

Methods: Participants (N =159) ages 8-16 (Meanage = 11.47 ± 2.51, 55.3% male) completed two self-report measures of aggression: The Reactive-Proactive Questionnaire (RPQ) scale and the Buss-Perry Aggression Questionnaire (AGQ). Participants also completed the Affective Reactivity Index (ARI) to measure irritability. Data were analyzed with SPSS (ver. 28) using Pearson correlations and MANCOVA.

Results: There was no significant correlation between age and total aggression scores (TAS) or total irritability score across the entire sample. For females only, age and RPQ TAS were significantly inversely correlated. An ANCOVA and post-hoc analyses showed that mean AGQ and RPQ TAS were significantly different between children who scored in the low and medium ARI irritability tertiles (p < .001), and between children who scored in the medium and high tertiles for the AGQ only (p < .05). On average, children in higher irritability groups reported higher TAS. There was no significant difference in the mean RPQ TAS found between the medium and high ARI tertiles (p = .12).

Conclusions: Irritability is a significant predictor of aggression; however, kids in the high irritability group may be slightly “worse” at rating their own aggressive behaviors, even though they are able to recognize their irritable feelings.The nonsignificant association between age and both irritability and aggression contradict findings of a general decrease in aggression throughout adolescence.

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research Areas


Courtney Kaplan, BA, Emma Cho, BS, Eileen Lee, BA, Maria Naclerio, BA, Jillian Russo, PsyD, Julianne W. Tirpak, PhD, Josephine Au, PhD, Daniel Dickstein, MD

Principal Investigator

Daniel Dickstein, MD

Affiliated Website