Cornell computer scientist Cristian Danescu-Niculescu-Mizil analyzed messages sent between players of strategy game Diplomacy to tease out early signs of future betrayal. A computer algorithm then predicted betrayal correctly 57 percent of the time, which is way better than the players themselves did.
From Science News:
One harbinger was a shift in politeness. 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, study coauthor and Cornell graduate student Vlad Niculae reportedJuly 29 at the Annual Meeting of the Association for Computational Linguistics in Beijing. Consider this exchange from one round:
Germany: Can I suggest you move your armies east and then I will support you? Then next year you move [there] and dismantle Turkey. I will deal with England and France, you take out Italy.
Austria: Sounds like a perfect plan! Happy to follow through. And—thank you Bruder!
Austria's next move was invading German territory. Bam! Betrayal.
"A few key signs betray betrayal" (Science News)
And for more on Diplomacy, don't miss this great episode of This American Life: