After reading all of Paul Ekman's books, watching all episodes of Lie to Me, and reading various other pop-science books, articles, posts, and so on, all on body language and lie detection, the only honest conclusion I could reach was that if you really want to know if someone's lying you better know the truth beforehand.
Though there is some science to the method, it ultimately relies on very complex combinations of all sorts of hints, clues, behaviors, all very ambiguous and hard to put to together. Applying this method to regular social interactions is even harder because you rarely get any feedback. You might determine that one person is lying but you might never get the chance to truly confirm your assessment. It's really hard to figure out what works and what doesn't.
You might have a chance at improving if you're a detective (maybe lawyer?) and get to often interview people, ask questions and immediately (or at least at some point) get feedback on whether your truthfulness assessment was right or not but if you're just some regular person who has ordinary social interactions it's much harder to become a human lie detector.
Though there is some science to the method, it ultimately relies on very complex combinations of all sorts of hints, clues, behaviors, all very ambiguous and hard to put to together. Applying this method to regular social interactions is even harder because you rarely get any feedback. You might determine that one person is lying but you might never get the chance to truly confirm your assessment. It's really hard to figure out what works and what doesn't.
You might have a chance at improving if you're a detective (maybe lawyer?) and get to often interview people, ask questions and immediately (or at least at some point) get feedback on whether your truthfulness assessment was right or not but if you're just some regular person who has ordinary social interactions it's much harder to become a human lie detector.