Though it's often hard to say with certainty if someone is lying or telling the truth, recent news describes questioning strategies and clues fraud investigators can use to improve their chances of exposing lies in investigative interviews.
But first, there are two widely-held beliefs to debunk.
"The classic idea that people in general believe ... is that liars give themselves away by gaze aversion, not looking you in the eyes, that they fidget, they change their posture, [or] pick on their clothes," Marcia Hartwig, a professor at the John Jay College of Criminal Justice is in New York City, told The Huffington Post. "All those ideas turn out to be false." Research studies on these types of nonverbal behaviors show they're not linked to lying.
Secondly, the tactic of listening to gut instincts may be similarly flawed, since false confessions uncovered by DNA tests show this belief held by police investigators has sometimes put innocent people in prison, according to The Why Files.
So what works?
Finding lies in fraud investigations is "all in the questioning," British professor Aldert Vrij told The Why Files in an email. "Through good interview techniques, deception may become apparent, but poor interview techniques are unlikely to elicit cues." Consider these tactics:
- Use reverse order recall. Asking interviewees to recall events in reverse order increases "cognitive load" during interrogation, making lying harder. This may expose contradictions, The Why Files noted. Further, reverse order recall often elicits new information from cooperative witnesses, whereas liars may repeat their stories.
- Ask unexpected questions. This method is helpful if you think someone's concealing something, The Huffington Post reported. It's based on the knowledge that liars plan their stories beforehand, particularly when they conspire with others. If you ask suspected liars questions they wouldn't dream of planning advance answers for, they may tell conflicting stories.
- Use evidence strategically. If you interview subjects without disclosing what evidence you have, liars may be more evasive while honest people volunteer information, The Huffington Post noted.
- Videotape interviews and use computers to spot micro-expressions. It's a tall order for investigators to ask questions while simultaneously analyzing speech patterns and body language. Here's where videotaping and computers can help. The face is "an incredibly valuable cue to deception if you know what to look for," Leanne ten Brinke, a University of California-Berkley scholar, told The Why Files. Some computers' vision systems use video cameras to shoot images of and decode facial expressions. And systems with advanced pattern recognition abilities can identify subtle difference between voluntary and involuntary facial movements that characterize sincerity, as FierceHealthPayer: Anti-Fraud reported.