More on the Pew poll:

The survey finds that constant movement characterizes the American religious marketplace, as every major religious group is simultaneously gaining and losing adherents. Those that are growing as a result of religious change are simply gaining new members at a faster rate than they are losing members. Conversely, those that are declining in number because of religious change simply are not attracting enough new members to offset the number of adherents who are leaving those particular faiths.

To illustrate this point, one need only look at the biggest gainer in this religious competition - the unaffiliated group. People moving into the unaffiliated category outnumber those moving out of the unaffiliated group by more than a three-to-one margin. At the same time, however, a substantial number of people (nearly 4% of the overall adult population) say that as children they were unaffiliated with any particular religion but have since come to identify with a religious group. This means that more than half of people who were unaffiliated with any particular religion as a child now say that they are associated with a religious group. In short, the Landscape Survey shows that the unaffiliated population has grown despite having one of the lowest retention rates of all "religious" groups.

There is much, much more. The characteristic here that most jumps out at me is that the fluidity of religious orientation in the U.S. is in itself reflective of American culture and history. Americans seem to be on the move all the time, responding to the tremendous economic and social pressures twisting the American family and workplace into new shapes. Religion seems to be less an influence than something subject to influence. More importantly, the poll seems to confirm the growing cosmopolitanism of this country. Most people here seem to go through multiple changes over the course of a life, and this is only possible in the giant (and hugely varied) complex of urban cores, inner rings, suburbs, and exurbs that characterize the majority of American communities.

One thing I have not found in the poll: how individuals change their religious affiliation throughout life. For instance, what changes correlate strongly with family life, with divorce, widowhood, urban single life, and so on. Who are the searchers, and who are the religious drifters?

I am also curious about the results given for the Buddhist "community". The split between immigrant Buddhists and American practitioners is profound. But this is not at all indicated in the poll results. Moreover, this split is significant, as the high-income, highly educated composite seems to mask the economic profile of immigrant Buddhists. Very interesting.