Dateline: November, 2006, Issue 3

How do jurors' beliefs about emotion influence murder/manslaughter verdicts?

Jury selection is an art based on science, with attorneys striking jurors they believe to be closed and resistant to the arguments they will be presenting. Jurors' beliefs about emotion, and the relationship between emotion and reason, have been found to affect determinations of guilt in a criminal trial.

A recent study by Spackman et al. (2006) found that jurors' beliefs about emotion and reason influenced their determination of whether a defendant was guilty of murder or manslaughter. In this study, mock jurors watched a videotape of a homicide case in which the defendant admitted to killing the victim, but claimed that his emotion at the time of the crime should be a mitigating circumstance. Deliberations revealed that jurors' beliefs about emotion and reason influenced whether they voted for murder or for manslaughter. The key difference was not whether emotions can overwhelm persons' rational faculties (on which jurors agreed), but rather about whether reason could coexist with emotion.

Jurors voting for murder believed that people can and should control their emotions with their reason. For these jurors, people can be impassioned and still make decisions based on reason. These jurors believed that people can simultaneously act from emotion as well as reason, and that the defendant should not have allowed himself to become so emotional or should have avoided situations in which he would become this emotional.

Jurors voting for manslaughter believed that people cannot operate from both reason and emotion simultaneously. For these jurors, being impassioned overwhelms rational thinking and precludes the possibility of acting from reason.

Source Spackman, M. P., Belcher, J. C., Cramer, L. & Delton, Y. (2006). A qualitative investigation of mock-jurors' theories of emotion and reason. Cognition & Emotion, 20, pp. 671-693