Bleg: The use of “role” where (formerly) we used “job” or “position”

Over the last five or ten years I’ve noticed that the word “role” is being used where I normally expected to see “job” or “position.” Just when did this happen, why, is it concentrated in certain sectors of the work force, and does it reflect a mere surface phenomenon, the use of a different word form, or does it reflect some shift in the implied semantics?

Consider these examples:

• The Acme Corporation is hiring for the following jobs...
• What’s your position at Acme?

Now “role” is likely to be used in both cases.

As I think about it, it seems to me that “job” is oriented toward some set of tasks and implies nothing about organizational context. One could be talking about a job at Acme or one could just as easily be talking about, say, unclogging the toilet at home (“it’s a nasty job”). “Position,” on the other hand, does imply an organizational context. One would never say, “Unclogging the toilet is a nasty position.” Nor, for that matter, would one say, “Decorating the Christmas tree is a fun position.”

“Role” also implies an organizational context. How, then, do we differentiate the use of “position” and “role”? Do we do so at all, sometimes, much of the time?

If there’s a difference, I think it’s between what sociologists call status and role (here I’m thinking of a classic discussion by Ralph Linton dating back to the 1930s). A status is a position within a social system having certain rights and obligations where a role is the set of behaviors used to enact that status. The social system could be a family, nuclear or extended, a social group, perhaps a neighborhood, or a bunch of people who sometimes gather together for various activities (e.g. the local rock musicians), a club, or some kind of business or governmental organization. In the case of well-defined organizations, statuses are likely to be specifically named and have specific responsibilities associated with them and listed in appropriate documents.

Language mavins (e.g. Ben Zimmer, John McWhorter), what’s up with current usage of the word?