This is hidden brain.
I'm Shankar Vedantam.
If you've taken part in religious services, have you ever stopped to think about how people become believers?
Where do the rituals come from?
And most of all, what purpose does it all serve?
When we ask these questions, we most often look to history or theology for answers.
But some social scientists are asking if we can better understand religion through the lens of human behavior.
If people behave in particular ways when exposed to different religious cues, can we use this information to work backwards and understand how those religious practices came about in the first place?
Can the rise and fall of religions tell us something about the needs of societies and how those needs change over time?
Today we bring you a favorite episode from 2018, God, religion, and the human mind.
This week on hidden brain.
Today, we're going to take an in depth look at religion through the work of Azim Sharif, a psychology professor at the University of British Columbia.
He studies religion not from the point of view of faith or spirituality, but from a psychological perspective.
He argues that human societies changed in a fundamental way several thousand years ago, and this change required a new psychological innovation.
So for the vast, vast history of our species, we didn't live in large groups.
We lived in very small groups, groups about 50 people, groups that never really got larger than 150.
And the reason for that is because, from a genetic standpoint, we're only built to be able to cooperate with as many people as we can know well.
So when you start having anonymous strangers in groups, when you start having people whose reputation you're unfamiliar with, what that means is that people can free ride on the group, they can cheat on the group with impunity.
And when you start having large groups of free riders and cheaters in a group, it can't sustain itself.
You need a level of cooperation between the people in a group for it to act and to work harmoniously.