Date of Degree


Document Type


Degree Name





Maureen O'Connor

Subject Categories

Psychology | Social Psychology


Anger; Decision-Making; Emotions; Insanity; NGRI; Self-Defense


Research indicates that the general public perceives the insanity defense negatively and inaccurately despite the infrequency with which it is pled and the realities often surrounding those who plead the defense. The negative and inaccurate perception of the insanity defense, combined with the potentially increased punitive judgments the defense elicits, suggests that emotion may play a role in perception of the insanity defense. In particular, the psychological literature on anger may contain answers to reactions toward the insanity defense. The current research explored the role of anger on punitive judgments toward a defendant pleading not guilty by reason of insanity (NGRI). Punitive judgment was assessed by measuring participants' perceptions of controllability (the extent to which the defendant's actions were perceived as preventable and controllable), punishment worthiness (the degree to which the defendant's actions were seen as intentional and perceptions of blameworthiness, punishment-worthiness, recklessness, and future recklessness), plea fairness, verdict fairness, verdict, and verdict certainty. In both studies, mock jurors read case vignettes in which a defendant pled NGRI. In Study One, potential jurors considered a plea and verdict of NGRI to be less fair than a plea and verdict of self-defense. In Study Two, participants in the medication non-compliance group felt more anger, after reading the vignettes, than participants in the prior history group. Additionally, anger was able to predict verdict to a statistically significant degree. Overall, the current research suggests that anger does play a role in negative perceptions of the insanity defense. Thus, it is important to further explore the role of emotions in insanity defense bias and effective bias reduction tools and strategies.