A new study out of Stanford University suggests that when people participate in synchronized activities—like the singing and chanting involved in many religious rituals—they become more likely to cooperate with one another. In one experiment, psychologists Scott Wiltermuth and Chip Heath had two groups of people walk around campus, one group walking normally and the other in-step. In another experiment, they had two groups listen to music on headphones and move cups back and forth in time to the beat. The members of one group all listened to the same music (so their movements were synchronous), while members of the other group listened to music with different tempos. After both experiments, members of the synchronized groups had a stronger sense that they were part of the same team, and they were more cooperative when they played economic games set up by the researchers—even making personal sacrifices, such as giving up their own money, to benefit the group. According to the researchers, who publish their results in the journal Psychological Science, "synchrony rituals may have therefore endowed some cultural groups with an advantage in societal evolution, leading some groups to survive where others have failed." —Heather Wax