A recent experiment demonstrates that synchronous actions knit the social fabric:

The results were striking: the simple act of tapping one’s hands in synchrony with another caused our participants to report feeling more similar to their partners and to have greater compassion for their plight: it increased the number of people who helped their partner by 31 percent and increased the average time spent helping from one minute to more than seven.

What these results suggest is that the compassion we feel for others is not solely a function of what befalls them: if our minds draw an association between a victim and ourselves — even a relatively trivial one — the compassion we feel for his or her suffering is amplified greatly.