Trials are often as partially showmanship along with the facts - both attorneys are trying to pick jurors who are most likely to go their way.

Moral outrage may be a secret weapon. The last time you were morally outraged you probably felt felt angry, but did you also feel disgust? Consider how you might feel in a court of law after watching a video of a heinous crime. 

Two new studies did, and they point to important legal implications when moral outrage is generated through the interactive effect of anger and disgust. The conclusion points to the need for judges to carefully consider the admissibility of evidence likely to elicit moral outrage in jurors in a world where phone and security cameras increasingly catch horrible crimes on camera and therefore may be entered as evidence.

"Camera phones are everywhere. There are so many more opportunities for crimes to be captured on video, which means jurors are being exposed to really emotionally charged evidence," said Jessica M. Salerno, Arizona State University New College of Interdisciplinary Arts and Sciences assistant professor. "When judges weigh the informational value versus the prejudicial value of the evidence, it is important to be very mindful that the negative emotions roused by emotionally disturbing evidence can make jurors more likely to vote guilty."

The paper outlines the studies that were designed to measure the effects of anger and disgust on moral outrage and probable implications in courts of law.

"After reading about jurors' dramatic reactions to emotionally disturbing evidence in court, we wanted to test how emotional stimuli might affect the jurors' judgment in court," Salerno said.

During the first study, participants were asked to read one of two vignettes, one of which dealt with sexual assault and the other that detailed Westboro Baptist Church funeral picketing. Participants reported measures of how disgusted and angry they felt on a scale of one to five.

Results showed that anger was a predictor of moral outrage when it occurred with at least a moderately high level of disgust and disgust predicted moral outrage when it occurred with at least a moderately high level of anger.

"It's the combination of the two that produces moral outrage," Salerno said.

In the second study, researchers hypothesized that the combination of anger and disgust would increase moral outrage and in turn influence confidence in a guilty verdict.

"There is no previous research, to our knowledge, that has tested whether moral outrage mediates the effect of disgust on subsequent judgments," she said. "Humans intuitively understand what moral outrage is. However, researchers debate its emotional components. We wanted to investigate the relationships between anger and disgust since emotions tend to co-occur with each other."

Study participants were shown a 20-minute presentation of evidence adapted from an actual murder case. Results showed that anger was a stronger predictor of moral outrage as disgust increased and disgust significantly predicted moral outrage at all levels of anger. Anger and disgust increased confidence in a guilty verdict through moral outrage, but disgust predicted moral outrage more consistently.

"Moral outrage affects confidence in a guilty verdict. All participants saw the same evidence, but those who experienced the combination of anger and disgust were more confident in a guilty verdict because they were more morally outraged about the crime," Salerno said. "This may not be in jurors control and they may not be aware that their emotions are influencing their decisions."

 "The Interactive Effect of Anger and Disgust on Moral Outrage and Judgments" is in Psychological Science. Source: Arizona State University