The more often a person tells a particular lie, the better he gets at telling it. There's not much difference between telling the lie for the fourth time and telling it for the fifth time. But the difference between it's first telling and its second-and all subsequent occasions-is immense. A virgin lie is a lie that's about to be told for the first time. The first time he tells the lie, the liar has to make it up. Think of an actor who not only has to play his part, but also has to write the lines he's to speak as he goes along.  The first time, the liar has to compute all the implications of what he's about to say. He has to figure out what his listener knows so that what he says doesn't conflict with this knowledge. He has to make sure it doesn't contradict what he might have said previously. As he speaks, he has to access memory to determine this at the same time he's finding just the right words to slide the lie by.
The virgin lie puts a massive computing load on the brain. We'd expect to see eye movements that accompany this
(#1 Eye Toggles). Besides the informational load, the virgin lie carries an increased emotional load. The liar doesn't know how the listener will react, and he'll be more susceptible to leaking the body language associated with lying (#5 Ten Soldiers of the Face). This is when he's most vulnerable to the lie detection machine (#9 Truth Serum and Lie Enhancers), because his sympathetic nervous system is revved up (#11 Keep that Coffee Cup Filled Up). After the liar has told the lie for the first time and gotten away with it, an enormous load is lifted from his mind. He's no longer writing the script; he simply has to perform, and he knows it's an act that works. He feels less performance anxiety, and because he's more confident, he's more fluent and persuasive. Like any public speaker, once he's got the basics down, he can work on his delivery, modulating the tone of his voice for maximum effect and focusing on the facial expressions and gestures that should enhance the message he wants to get across.  This is why the virgin lie is so valuable to interrogators. Paul Lucas, the forensic psychiatrist in my new book Virgin Lies, continuously interrupts the suspect and deflects him to other topics when he attempts to deny he knows where a kidnapped girl is hidden, because Paul wants to ambush him with the question at a time when the suspect's off-balance.
The basic strategy is not to give the liar a chance to tell the virgin lie until you're ready. Get him to tell the lie at a time and place of your choosing, when you can surprise him when his defenses are down (#12 Ambush Questions). Once he's told the virgin lie, hold him to it. Make sure you both remember exactly what he said. Lawyers, if they're in a restaurant and someone says something they want remembered, "accidentally" knock over a glass of water: Everyone remembers the moment. You want to mark the event, too, because once he's told the virgin lie, he's married to it for the rest of his life. | 
