Education and Human Sciences, College of (CEHS)


First Advisor

Hideo Suzuki

Date of this Version


Document Type



Poh, Y. T. (2020). Relationship between personal distress and aggression is moderated by nucleus accumbens volume [Unpublished master's thesis] University of Nebraska-Lincoln


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Arts, Major: Educational Psychology, Under the Supervision of Professor Hideo Suzuki. Lincoln, Nebraska: December, 2020

Copyright © 2020 Yuan Ta Poh


Studies into the relationship between empathy and aggression has found that the effect is weak (Vachon et al., 2014). This weak relationship is observed through aspects of empathy interacting with aspects of aggression in different ways depending on the types of empathy and aggression being measured. The present study utilized neuroimaging approach to examine the relationship among empathy, aggression and nucleus accumbens (NAc) volume. Forty nine college students underwent magnetic resonance imaging scans and completed the Interpersonal Reactivity Index as well as the Reactive-Proactive Questionnaire. Using FreeSurfer, bilateral NAc volumes were obtained for statistical analysis. Hierarchal regression analyses were utilized to test the interaction between either proactive or reactive aggression, left NAc volume, and right NAc volume in predicting four dimensions of empathy. Results indicated that the interaction between left NAc volume and right NAc volume was significant in predicting perspective taking levels. In addition, right NAc volume positively predicted empathic concern levels. Finally, aggression was associated with personal distress, depending on the volume of the left or right NAc. Specifically, there was a positive association between personal distress and proactive aggression in participants with increased left NAc volume whereas the association was negative in those with decreased left NAc volume. Finally, a negative association was found between personal distress and aggression in participants with increased right NAc volume, but this association was positive among those with decreased right NAc volume. Thus, it is found that NAc volume moderates the relationship between personal distress and aggression.

Advisor: Hideo Suzuki