Science News interviewed Cristian Danescu-Niculescu-Mizil in a zippy article about his work with Cornell PhD student Vlad Niculae and colleagues at University of Maryland and UC-Boulder on linguistic signals of upcoming betrayals. Using the online game of Diplomacy as the source of data, the team found that "Players who were excessively polite in general were more likely to betray, and people who were suddenly more polite were more likely to become victims of betrayal"; also, "An increase [in] planning-related language by the soon-to-be victim also indicated impending betrayal, a signal that emerges a few rounds before the treachery ensues. And correspondence of soon-to-be betrayers had an uptick in positive sentiment in the lead-up to their breach." But "more important than the clues themselves is the shift in the balance of behavior in the relationship. Positive or negative sentiment of one player isn’t what matters, it’s the asymmetry of the behavior of the two people in the relationship." The resulting system built by the Cornell researchers and their co-authors Srijan Kumar and Jordan Boyd-Graber was more accurate than humans at detecting future betrayal.
The article starts with the observation that "Whether it’s Katy Perry poaching dancers from once-BFF Taylor Swift or Clytemnestra orchestrating the murder of her husband Agamemnon, betrayal is a dark, persistent part of the human condition. Unlike garden-variety deception, betrayal happens in established relationships, destroying trust that has developed over time. It’s usually unexpected, and it yields a unique, often irreparable, wound. In fact, betrayers have a special place in hell, literarily: In Dante’s Inferno, they occupy the ninth and final circle; mere fraudsters dwell in the eighth."
https://www.sciencenews.org/blog/culture-beaker/few-key-signs-betray-betrayal