It is common to fret about the level of politeness owed to that group of people termed the “casual acquaintance.” These are usually work/school colleagues with whom we have conversed once or twice, but have never “hung out” with one-on-one, and with whom we have no intention of hanging out one-on-one. The difficult behavior questions arise when we run into these acquaintances unexpectedly and must decide on the level of interaction to initiate. Obviously, we do not wish to rudely ignore these people, but both they and we usually know that the chances of true friendship blossoming are negligible. So do we simply say hello? Do we stop and chat? Uncertainty about the boundaries of the acceptable often ends up producing extreme anxiety and discomfort in both parties.
Fortunately, norms do exist. Our interactions with acquaintances are predictable and easy to chart. The key insight is that casual acquaintance interaction is spatially determined. Where we run into the casual acquaintance, rather than any facts about ourselves or the other person, is the sole factor governing the extent to which we will interact with them. Obviously, for the many times a day we pass them in the hall at work, we will not keep acknowledging them over and over. But the farther away from our shared institution the run-in occurs, the greater the extent of our involvement will inevitably be. The end result is that the casual acquaintance is actually only a casual acquaintance the nearer to the shared institution one meets them. As one gets progressively further away from the shared institution, the casual acquaintance is steadily transformed into a friend. Friendship and acquaintanceship are, therefore, geographic constructs.
Here, then, is a chart showing the geographic determinants of our interactions with casual work/school acquaintances: