Vanessa Van Edwards breaks down the surprise micro-expression, a brief facial cue that signals astonishment. When someone hears new information and says they didn't know, genuine surprise on their face means they're telling the truth. No surprise means they already knew.
Surprise is a really fun micro expression. It's astonished, stunned, startled. It's neither positive nor negative, because you can be negatively surprised or positive surprised. If it goes too negative, it becomes fear. The moment that someone is negatively surprised, they typically become afraid. So it's this really interesting little emotion because it's somewhere in between. And there's really only one big use case for surprise, which is, do you want to know if someone's telling you the truth? If you give someone a piece of news and they say, I didn't know, with surprise, you know they didn't know. But if they don't, are surprised and say, oh, I didn't know, and there's an absence of that surprise, they probably knew.
