Studies show that after walking in step with someone, tapping to the same beat, or even just moving a plastic cup side to side in unison, people cooperate more in an economic game, sacrifice more to benefit the greater good, and are more likely to help a stranger. Even babies show this effect. When fourteen-month-olds are bounced to music, facing an experimenter who bounces in sync, they are more likely to later help that experimenter pick up dropped markers.
