Anger may be just as effective at motivating people to volunteer as sympathy, according to a recent study.

"Although there are many reasons why individuals help, empathy is prominent. Empathy occurs when an individual has a similar response to a suffering person and this is usually sadness," Robert Bingle, researcher and professor at Appalachian State University in North Carolina, said in a statement. "Empathic sadness motivates a person to help in order to alleviate the other person's suffering and to alleviate one's own discomfort."

The study focuses on circumstances when empathy elicits anger.

For the study, researchers administered two questionnaires focused on the nature of those reporting empathic anger using a new measure, the "Revised Empathic Anger" scale.

Based on the results of In Study 1 (involving 132 participants) found that those scoring high on empathic anger were publically spirited and more likely to support community projects and organizations as a way to affect change rather than charitable volunteering. Study 2 (involving 152 participants) found those reporting high empathic anger were not aggressive people, but were concerned and altruistic individuals who rejected group-based discrimination and inequality among groups.

Bingle said their findings add a new dimension for volunteering.

"Empathic anger is probably a more extreme or intense motive than others that have been described or studied in the previous research on volunteering and prosocial behavior," he said.

"By developing our understanding of empathic anger we can better appreciate why some volunteers are motivated to assist certain social causes," he added. The new scale provides opportunities for future research to study the nature of empathic anger, its development, and it journey across time."

The findings were presented at the British Psychological Society annual conference on May 7, at the International Convention Centre in Birmingham.