Graduation Date
Fall 2025
Document Type
Thesis
Program
Master of Arts degree with a major in Psychology, option Academic Research
Committee Chair Name
Dr. Christopher Walmsley
Committee Chair Affiliation
Cal Poly Humboldt Faculty or Staff
Second Committee Member Name
Dr. Carrie Aigner
Second Committee Member Affiliation
Cal Poly Humboldt Faculty or Staff
Third Committee Member Name
Carrie Moses
Third Committee Member Affiliation
Community Member or Outside Professional
Keywords
Psychology, Applied behavior analysis, ABA, Behavioral psychology, Acceptance and commitment training, Acceptance and commitment therapy, Aggression, Externalizing disorders, Single case design, Multiple baseline
Subject Categories
Psychology
Abstract
Acceptance and Commitment Training (ACT) is a contemporary mindfulness intervention traditionally practiced in psychotherapy but recently has been adopted by practitioners in Applied Behavior Analysis (ABA) due to its functional foundation and theoretical grounding in Relational Frame Theory (RFT). ACT interventions are tailored to develop and continually exercise an individual's psychological flexibility while, in turn, decrease levels of experiential avoidance (EA). Literature surrounding ACT and its applications in ABA showcase data supporting its effectiveness for treating a diverse range of behaviors. Elevated levels of EA have been linked to a variety of maladaptive behaviors, one being aggression. Aggression is a primary symptom of Oppositional Defiant Disorder (ODD), an externalizing disorder characterized by persistent defiance and hostility towards others. The current study evaluated a seven-week ACT intervention on aggressive behavior in a school setting using a single case design methodology and a multiple baseline across settings design. One participant with a diagnosis of ODD was recruited. Three forms of aggression – noncompliance, verbal aggression and physical aggression – were measured using partial interval recording. Individual ACT treatment sessions were implemented twice, in the morning and afternoon, and aggression was measured immediately after through direct observations. Data showed a clear decrease in noncompliant behaviors in both settings following introduction of the ACT treatment, indicating a functional relationship between the variables. Verbal aggression showed a decrease in aggression in the morning sessions; however, afternoon sessions show ambiguity, making a functional relationship unclear. Few occurrences of physical aggression were recorded, making inferences on this measure unfeasible. Further research is recommended to expand understanding of ACTS effectiveness in reducing challenging behaviors.
Citation Style
APA
Recommended Citation
Rodriguez, Isabelle C., "Acceptance and commitment training for reducing aggressive behaviors for children diagnosed with externalizing disorders" (2025). Cal Poly Humboldt theses and projects. 2521.
https://digitalcommons.humboldt.edu/etd/2521