In a New York Times article on lying, scientists suggest that excessive detail and meandering narratives help liars avoid detection:
The new work focuses on what people say, not how they act. It has already changed police work in other countries, and some new techniques are making their way into interrogations in the United States.They are also training police to gradually introduce known facts during interrogations, however, which makes it tricky because if you are purposefully trying to embellish to hide a lie, you need to be extra careful that the embellishment is not about something easily ascertainable. Embellishments should be about things no one could possibly know about, like your feelings, the underwear you wore, how you slept the night before, etc. The worst would be for people to say random things like "it was a full moon" when there was no moon at all, etc. Check yourselves, fellow sociopaths.
In part, the work grows out of a frustration with other methods. Liars do not avert their eyes in an interview on average any more than people telling the truth do, researchers report; they do not fidget, sweat or slump in a chair any more often. They may produce distinct, fleeting changes in expression, experts say, but it is not clear yet how useful it is to analyze those.
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Kevin Colwell, a psychologist at Southern Connecticut State University, has advised police departments, Pentagon officials and child protection workers, who need to check the veracity of conflicting accounts from parents and children. He says that people concocting a story prepare a script that is tight and lacking in detail.
“It’s like when your mom busted you as a kid, and you made really obvious mistakes,” Dr. Colwell said. “Well, now you’re working to avoid those.”
By contrast, people telling the truth have no script, and tend to recall more extraneous details and may even make mistakes. They are sloppier.
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In several studies, Dr. Colwell and Dr. Hiscock-Anisman have reported one consistent difference: People telling the truth tend to add 20 to 30 percent more external detail than do those who are lying. “This is how memory works, by association,” Dr. Hiscock-Anisman said. “If you’re telling the truth, this mental reinstatement of contexts triggers more and more external details.”
Not so if you’ve got a concocted story and you’re sticking to it. “It’s the difference between a tree in full flower in the summer and a barren stick in winter,” said Dr. Charles Morgan, a psychiatrist at the National Center for Post-Traumatic Stress Disorder, who has tested it for trauma claims and among special-operations soldiers.