3. Ask Unanticipated Questions

Start off with expected questions. This is non-intimidating and gives you info — but more importantly, it gets you a baseline. Then, throw them a question that’s easy for a truth teller to answer but that a liar would not be ready for.

For example, ask an underage-looking person at a bar how old they are and you’ll hear a confident “I’m 21.” But what if you asked them, “What’s your date of birth?” That’s an exceedingly easy question for someone telling the truth, but a liar will likely have to pause to do some math. Gotcha