I was astounded to hear about this principle years ago, but could never remember the name. Apparently it's also called "expectancy confirmation". It takes a second to realize what's so amazing about the idea: when you expect somebody to behave a certain way, not only will you treat them differently, but *they'll subconsciously help you confirm your bias*. So expecting somebody to lie to you makes them more likely to actually do so!
For such a mind-blowing principle, it's documented really poorly online. The book search result was the closest thing I could find.