I really do mean to ask, how do you deal with the two concrete situations given above?
I am inclined to "yield first", although it doesn't often (or hardly ever) happen in practice that I'm walking on a path that narrow.
When I'm on a bicycle on a shared footpath, pedestrians are usually inclined to yield to me, and then I allow them to yield (they walk on one side of the path and I cycle past them); or you could say I yield i.e. I cycle around them. I slow, slow to a stop, or dismount when necessary (e.g. on a single-lane footpath under a bridge, when passing small children or off-leash dogs, or on a pedestrian side-walk).
Sometimes I drive a car on a single-track road. There is a (unwritten?) convention for which car is supposed to yield in that case, i.e. it's supposed to be whichever car is able to yield the most easily:
- The car which has a lay-by in front of it, which it can pull into
- The car which is closest to the lay-by behind it (i.e. the car which has most recently passed a lay-by) into which it can reverse
- The car which can most easily reverse (e.g. the car which will be reversing down-hill rather than up-hill, or the smaller car)
Sometimes I stop for 4 ½ seconds to see whether the other car (which is probably driven by someone who's more familiar with the road than I am) goes into reverse, and if not then I start to reverse.
The more abstract problem here might be described as, the correct action to take when you and another have conflicting interests. An answer to that is appreciated as well ...
I don't see this as a conflicting interest. I want to get around in a friendly and more-or-less cooperative way, I want to be non-aggressive and I don't want to frighten people. I assume (and my experience has confirmed) that these ambitions are socially acceptable and not a "conflicting interest".
When one car yields to another is conventional for both drivers to do a small hand-wave to the other as they pass each other (each to acknowledge the other's politeness and savoir faire perhaps).
On foot if I make eye-contact with someone (outside a city) then I'm likely to say "Good day!" to them (and vice versa, they do too). Someone said once that according to the older and more formal rules of politeness in this country it's conventional that it should be the more junior person who should be the first to say "Good day!"; but I'm happy ignore that and wish a good day to anyone, older or younger.