How can you tell if someone is lying?
Most of us can’t reliably tell when a romantic interest is actively signaling their mutual interest.  If we can’t get cooperative activities right, most of us don’t have a chance to spot a liar through nonverbal cues.  The fact is that random effects are huge when dealing with people.  Is that person you’re interrogating not showing emotion because they’re a psychopath, or because they were taught not to display emotion?  Is someone not looking a cop in the eye because they are lying, or because staring someone in the eye is perceived as defiance in many cultures and they don’t want to anger the cop?  We’ll probably never be perfectly accurate at spotting lies.  A bunch of biometric measurements might help, but current polygraph techniques can allegedly be beaten with training.  If trained polygraph techs with special equipment can be beat I don’t know what rules of thumb we’re ever going to give to the general public that will work.<p>If you know someone really well, you might have a decent chance of knowing when they are acting unusual.  Such is the case with parents and teenagers, but suspicion often gets the best of the parents and they misinterpret the cues that they spotted.<p>A good method would seem to be to catch someone on a logical contradiction, but that has issues when someone is under emotional distress.  And emotional distress tends to appear often when someone is innocent but is afraid the evidence points towards them.  The family cat may have knocked over Mom’s favorite vase, but the child is less interested in the truth and more interested in avoiding a spanking- so they embellish whatever story they had (in a misguided attempt to make it more believable), which introduces contradictions that the mom notices.  The kid technically lied with the embellishments but was innocent of breaking a vase, and gets spanked when they didn’t deserve it.  Then imagine the kid’s emotional distress being even higher the next time something happens.<p>I’m sure that there are a lot of learned people out there that study lying, but I agree with the article’s main theme that most of us can’t reliably tell when our why someone is lying, and we’re overconfident in our abilities.