It is my guess that what happens psychologically when a question is not answered links in with your earlier point about spontaneity and the 'process' of dialogue...
I think it is also possibly contingent on both the nature of the question and the motivation of the questioner.(By 'nature' I really mean how the question is itself phrased).
There is courteous element that looks for acknowledgement at least and, yes, we are conditioned psychologically to conform in a sense - to respond even on an emotional level.
Are we genuinely seeking to 'know' and/or 'answer' eachother's questions or is it enough to recognise the meditative freedom afforded by having quasi-philosophical questions themselves?
If our motivation for asking questions is, essentially, of a social nature; do we then revise our questions to conform to a language of 'anticipatable' answers?

Regards,

Katy