Re Bunsen Burner’s #60, actually Germany has quite strict standards about which academics can call themselves Dr. and a great many doctorates held by Americans will not suffice. The last I knew, Cambridge and Oxford were not willing to acknowledge a Ph.D. from outside Oxbridge, but within England–e.g., University of London. This is ridiculous of course, but it was the practice. Perhaps it has changed now.
bearcatfan, I am sure that the AP style you referenced is correct, just using “doctor” to refer to medical doctors.
Within academia, M.D., D.O., J.D. and other degrees that do not require a significant addition to the body of knowledge, just a level of mastery of known concepts, do not carry the relative weight that they do outside. That’s fine.
The University of Chicago practices a kind of inverse snobbery, where the professors are referred to as Mr. or Ms. It is somewhat unsettling to call a Dean there, and have the phone answered “Mr. X’s office.”
The discussion reminds me of a comic–Doonesbury, I think–where a medical emergency occurs during a performance and the call “Is there a doctor in the house?” is answered by someone saying “I have a Ph.D. in English Literature.”
One circumstance where I would not use my title (outside of social settings, where I don’t use it either) is when flying–the flight attendants need to be able to differentiate a medical doctor from an academic doctor.