Does Religion Reduce Aggression?

Some religious believers argue that religious activities such as prayer and reading the Bible can reduce agression.

However, in an article in the December 2008 issue of Psychology Today, a study was performed by Mark Leach of University of Southern Mississippi that suggests differently. 42 Christians spent five minutes reading a Bible passage or meditating. They then selected the intensities of electrical shocks to give to opponents in response to shocks that they themselves received. The Christians who had been "primed for peace" set the same intensity level as the control group who merely read the New York Times for five minutes.

According to the article, "[W]hile those who claim to practice religion in the service of God are no more peaceful than the rest of us, they believe that they are."

It's an interesting conclusion, but I can't find the actual study results for further scrutiny, and the methodology could be flawed. After all, certain passages of the Bible are more aggressive than others, and the same could be said of New York Times articles. Would reading about, say, the slaughter of the Canaanites by God's chosen people make someone more likely to turn up the juice on someone who's just shocked her, compared to reading, say, a pastoral Psalm? What about reading an NYT article about a Christian cult member found guilty of abusing a child compared to a milder political analysis? I would need to see the study before making any firm conclusions.