Can you spot when someone is lying? A new computer program reveals the behaviors and verbal tics that are more common among liars.
Researchers at the University of Michigan have “taught” an artificial intelligence machine to recognize body movements and language more common to liars than people telling the truth. The computer viewed 120 videotapes of witnesses testifying in court cases. In each instance, the computer was told whether the witness was being truthful or prevaricating.
When the machine was asked to decide on its own whether a witness in a new video was being deceitful, it got the right answer 75 percent of the time.
“I think this could be a tool to assist people working in law enforcement, security and customs,” says Rada Mihalcea, one of the machine’s developers and a professor of computer science and engineering at the University of Michigan.
The computer found that certain behaviors, facial expressions and verbal styles were more common among liars:
Scowling or grimacing of the whole face.
This was in 30 percent of lying videos vs. 10 percent of truthful ones.
Looking directly at the questioner.
In 70 percent of deceptive clips vs. 60 percent of truthful.
Gesturing with both hands.
In 40 percent of lying clips, compared with 25 percent of the truthful.
Speaking with more vocal fill such as "um."
This was more common during deception.
Distancing themselves from the action.
Liars were more likely to use words such as "he" or "she," rather than "I" or "we," and using phrases that reflected certainty.
While the artificial intelligence machine could help law enforcement or TSA workers, the rest of us don't need a computer to sense when someone we know is lying. Our own gut instincts are reliable.
Your brain works very much like the artificial intelligence machine, says Cynthia Cohen, a Los Angeles trial consultant. It’s working in real time, comparing the way the person in front of you usually behaves and talks to what they’re doing right now.
You may not be able to put your finger on it, but you know "something is off," says Cohen. "
"Often it’s a mismatch between what the person is saying and their expression. And you’re picking that up subliminally."