Dr. David DeSteno

It's also the case that

Every day during the seven days of Shiva, your community has to come to your house.

And prayers are said in what's called a minyan, which is a minimum of 10 people.

So people come and they will say prayers together.

And while they're saying prayers, they're kind of swaying in unison, saying the same words in unison.

That's something in psychology we call motor synchrony.

What is motor synchrony?

It's simply moving your body in synchrony with someone else.

So in my lab, we've shown that if we bring people in and we have them engage in motor synchrony, so let's say you and I, Andrew, don't know each other, we sit down, you put on earphones, I put on earphones or headphones, and in front of us is a little sensor.

It's really not a sensor, but it looks like a little pad.

And we play you tones, and you're supposed to tap that sensor every time you hear the tone.

And in some conditions, we have these people who have never met.

Here, it's simultaneous tone, so they're tapping in unison.

In other cases, they're completely random, and so they're not synchronized at all.

Through a whole set of shenanigans that I won't go into, what then happens is one of the persons is put in a situation where they need help to complete a task, or they're going to be stuck there for a long time and not get credit for this study.

If we had tapped in unison, people report feeling more connection to this person.

They report feeling more compassion for their plight.

And by 30% more, they're willing to go help that person, spend their time taking on some of that person's burden.

Now, if you ask them, why do they do this?

They'll say, you know, I...