This is hidden brain.
I'm Shankar Vedanta.
On a hot summer morning, worshipers gather at the First Baptist Church in Washington, DC.
They've come in their Sunday best, sharp suits and flowing skirts, shined dress shoes, and spiky high heels.
They've come to be among friends and family, to pray and sing and rejoice after a long and hectic week.
If you've taken part in a religious service at a church or another house of worship, have you ever stopped to think about how it all came to be?
How did people become believers?
Where did 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.
What 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 different religions tell us something about the needs of societies and how those needs change over time?
Today, we're going to take an in depth look at these provocative ideas 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 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.