Graduation Year
2026
Document Type
Open Access Senior Thesis
Degree Name
Bachelor of Arts
Department
Psychology
Reader 1
Jennifer Ma
Reader 2
Egamaria Alacam
Terms of Use & License Information
Abstract
Trauma can profoundly influence behavioral presentation, yet jurors often rely on demeanor as a diagnostic cue for guilt, credibility, and remorse. Such reliance poses risks within a legal system that seldom equips jurors to interpret trauma related behaviors accurately. The proposed study will examine how two trauma-linked affective presentations– overemotionality and flat affect– shape juror perceptions of credibility and guilt, and whether expert psychological testimony about trauma-related affect can mitigate these biases. Online survey participants will read one of five trial vignettes with varying defendant conditions (flat affect vs. overemotional) and varying expert testimony conditions (present or not present) and will then provide verdict decisions and rate the defendant’s credibility. It is predicted that overemotional and flat affect defendants will receive more guilty verdicts and lower credibility ratings than control defendants, but expert testimony on trauma may be able to counteract these negative biases. This research may contribute to the growing literature on trauma-informed courtroom practices and offer empirical insight into how expert witnesses may help protect defendants’ Sixth Amendment right to an impartial jury. Ultimately, the findings aim to clarify whether juror opinions are swayed by defendants’ nonverbal demeanor, and whether or not expert testimony can mitigate these potential biases.
Recommended Citation
Goldman, Jensen, "The Silent Language of Trauma: Defendant Behavior, Juror Bias, and Expert Testimony" (2026). Scripps Senior Theses. 2909.
https://scholarship.claremont.edu/scripps_theses/2909
