he believes the relationship is causal, not just a correlation and it's not to do with belief, but with being part of a community of belief.
he doesn't know what makes faith communities civically exceptional. not even networks of environmentalists, that share interests beyond themselves too, score so well.
putnam thinks that the evidence shows the link between civic engagement and religiosity in the uk is pretty much the same as in the US, notwithstanding that british religiosity is obviously far less pronounced
(sadly what isn't linked to in the article is the source material that leads robert to these conclusions - although the biog link above does say he is currently working on three major empirical projects: (1) the changing role of religion in contemporary America, (2) the effects of workplace practices on family and community life, and (3) practical strategies for civic renewal in the US in the context of immigration and social and ethnic diversity)
found via respublica.org.uk