@roger,
I don't answer until I know who it is, and even most of that. We are not alone - I read some article which I referred to here after I read it (which article, no link now) about the history of polling, with lots of explanation of pros and cons, one of the typically long articles in the New Yorker. Part of the punch of that was about how many of us don't answer regular phones, as those are going away in handbaskets, and many of the rest of us have in line phones that can give us a clue who is calling. I gather polling doesn't work for smart phones, not sure.