And the popularity of this account shouldn't come as a surprise. Turns out, humans are wired to eavesdrop. Especially when the information is limited. This paper in Psychological Science, for example, suggests that it's harder to not listen to a conversation when someone is talking on the phone (we only hear one side of the dialogue) than when two physically present people are talking to each other.
This has a lot to do with our information processing, and the way the brain allocates attention. We are especially drawn to gaps in information. This is known as the "information gap" theory of curiosity and was first described by George Loewenstein in the early '90s. In this study, scientists demonstrated that subjects listening to only one side of a conversation — what they call a "halfalogue" — showed decreased performance on a range of cognitive tasks that require undivided attention. The researchers concluded that it's the "unpredictable nature" of the halfalogue that makes it so appealing.
In other words, we can't help but eavesdrop when we don't know what the conversation is about or where it's headed. Which, I guess, happens a lot in Ubers!
