The Pew Research Center has offered its own theories.
One explanation Pew gives is that our nation is experiencing political backlash – "that young adults, in particular, have turned away from organized religion because they perceive it as deeply entangled with conservative politics and do not want to have any association with it."
More specifically, Pew explains, this brand of religion and politics is out of step with young adult views on same-sex rights and abortion.
Postponement of marriage and parenthood, broader social disengagement and general secularization of society may also play a part, according to Pew.
But to be religiously unaffiliated doesn’t require a lack of faith or spirituality, researchers say.
Yes, the "nones" group includes those who might call themselves atheists or agnostics. But it also accounts for many – 46 million people – who don't belong to a particular group but are, in some way, religious or spiritual, according to Pew.
This is all part of the changing face of society and faith, and where the Internet fits in is just part of a complicated puzzle.
The evolving landscape includes plenty of people who go online in search of spiritual and religious sustenance, said Cheryl Casey, who delved into the issue for her 2006 dissertation.
Casey, now a professor of media, society and ethics at Champlain College in Vermont, wrote about the “revirtualization of religious ritual in cyberspace” and the morphing relationship between technology and religion.
That Downey would find a correlation, that the Internet is increasing disaffiliation, makes perfect sense to her.
"The institutional control over the conversation is lifted, so it's not just a matter of more churches to choose from but more ways to have that conversation and more people to have that conversation with," she said Wednesday.
People move away from formal affiliation and toward what she calls "grass-roots religious exploration," where "the nature of the medium allows for those conversations to grow organically."
Innovations have long played a part in influencing religion, she said, and will continue to.
Something she wrote back in 2006 said it best.
“When a new technology, such as the printing press or the Internet, unleashes massive cultural change, the challenge to religion is immense. Cultural developments change how God, or the ultimate, is thought of and spoken about,” she wrote.