A Duke University professor's new analysis of decades' worth of data suggests that American religious belief is getting gradually weaker and less widespread than it once was.
In a book to be released this week, Mark Chaves argues that Americans have less trust in and growing dissatisfaction with religious leaders. He says that makes people less likely to attend regular worship services than they were a generation ago.
Chaves, who directs the National Congregations Study, says religion is still a powerful force in American life, especially for those who remain regular practitioners.
But the number of people who belong to no religious group has grown substantially, especially in the last two decades.
Chaves found that as many as 20 percent of all Americans say they don't belong to any religious group, compared with around 3 percent in the 1950s.