From PhysOrg:
A series of studies showed that people who were provoked by insulting comments from a stranger showed less anger and aggression soon afterwards if they prayed for another person in the meantime. The benefits of prayer identified in this study don't rely on divine intervention: they probably occur because the act of praying changed the way people think about a negative situation, said Brad Bushman, co-author of the study and professor of communication and psychology at Ohio State University. “People often turn to prayer when they're feeling negative emotions, including anger,” he said. “We found that prayer really can help people cope with their anger, probably by helping them change how they view the events that angered them and helping them take it less personally.”
The power of prayer also didn't rely on people being particularly religious, or attending church regularly, Bushman emphasized. Results showed prayer helped calm people regardless of their religious affiliation, or how often they attended church services or prayed in daily life. Bushman noted that the studies didn't examine whether prayer had any effect on the people who were prayed for. The research focused entirely on those who do the praying. Bushman said these are the first experimental studies to examine the effects of prayer on anger and aggression. He conducted the research with Ryan Bremner of the University of Michigan and Sander Koole of VU University in Amsterdam, the Netherlands. It appears online in the journal Personality and Social Psychology Bulletin and will be published in a future print edition.
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