Dateline: December, 2008, Issue 3
At times, defendants admit committing a crime, but argue that they should not be considered legally responsible because they have an excuse. Some excuses are more compelling than others, and some jurors are more compelled by the excuses than others.
Heath and colleagues (2001) compared excuses that were self-inflicted to those that were not self-inflicted. Jurors judged a defendant who gave the excuse of Cocaine Dependency Disorder (a highly self-inflicted condition) as guiltier than a defendant who gave the excuse of Posttraumatic Stress Disorder (PTSD) (a condition inflicted by others). The more defendants were responsible for the condition they claimed mitigated their guilt, the less persuasive the excuse.
Higgins and colleagues (2007) investigated whether younger or older jurors were more persuaded by excuses. Jurors learned about a defendant in an assault case who either gave an excuse of Cocaine Dependency Disorder or PTSD. Younger and older jurors equally (and highly) believed the defendant with Cocaine Dependency Disorder was responsible for the assault. However, older jurors were more certain of their verdicts and felt the defendant with PTSD was more responsible for the assault than did younger jurors.
Excuses involving self-inflicted conditions are less persuasive than excuses involving conditions inflicted by others. Younger jurors are more persuaded than older jurors by excuses based on conditions inflicted by others.
Source Heath, W.P., Grannemann, B. D., Peacock, M.A., & Dulyx, J. (2001). Effects of considering who and why the defendant attacked. Journal of Applied Social Psychology, 31, pp. 860-887.
Source Higgins, P. L., Heath, W.P., & Granneann, B. D. (2007). How type of excuse defense, mock juror age, and defendant age affect mock jurors' decisions. Journal of Social Psychology, 147, pp. 371-392.