A matter of collaboration

Can we really speak of a collective intelligence merging from the action of scattered users? Can we speak about a will of collaboration or, maybe, it's just that particular and collective interests are matching together? Do we contribute because social tools are useful for us, because we love the idea of open content or because we are trying to achieve a digital reputation? To which extent one or the other motivations are working?
I hear quite often that users begin to use social software because of a personal interest, like the advantage of ubiquity when bookmarking at del.icio.us, and the sum of all these interest is what make new value for the community. Right, but these instrumental goals come together with other social goals, because users are aware that there are not taking notes in their personal notebook and also aware that one tag or another can make more people find these personal bookmarks.
So instrumental and social goals meet together when a user is deciding whether to collaborate and make open its content, links... or keep it in his own folders. Peter Kollock Social dilemmas, anatomy of cooperation is maybe a good perspective to study what's happening between the individual and the collective, even more when we see that this author has also edited a book where the nature of virtual communities is also explored: Communities in cyberspace
And on top of this we have the digital divide matter: a few days ago, danah boyd talked about a first PEW report about adults footprints. Digital footprints is more about privacy than contributing and adding value, but the idea is that adults are very likely to leave information about themselves but they are saying just the opposite, specially to their children. A few days later another report is commented in the same blog. This one is about young people, "teens are much more protective of the content they post online than adults are".