How has religion evolved since early people

Many Catholics reveled in the pope's whirlwind visit to the East Coast of the United States last month. But as the devout return to life as usual, nonreligious Americans may be left scratching their heads, wondering what all the fuss was about. 

The vast majority of the U.S. population does not belong to the Catholic Church, and a growing percentage of Americans are not affiliated with any organized religion at all, according to a recent survey by the Pew Research Centers. So the question then becomes, what role does religion play in today's American society? Perhaps oddly, that question can be answered by a group of people not usually associated with religion: scientists.