Uncertainty reduction theory (URT) was originally created to explain the communication process that occurs when two strangers interact. Charles Berger and Richard Calabrese (1975) observed that when we interact with strangers, we experience uncertainty because we don’t really know what to expect. Berger and Calabrese claim that as the interaction proceeds we gain information that quickly reduces our uncertainties. However, there have probably been times where you didn’t really worry about finding out anything about the stranger because you never expected to see the person again or it wasn’t someone with whom you wanted to pursue a relationship. URT provides explanations for these and other behaviors when people interact with someone new.
Redmond, Mark V., "Uncertainty Reduction Theory" (2015). English Technical Reports and White Papers. 3.