If you can always tell when someone's lying, you might just be a wizard - that's what scientists say anyway.
After testing more than 13,000 people, researchers in the US found just 31 who could always tell when people were lying or telling the truth.
Those "wizards", as the scientists called them, picked up on tiny changes in facial expressions which most of us miss to see if someone was fibbing.
They hope by studying the wizards, they can train police to spot liars too.