How do you know if someone is lying?
You usually don't. Research has shown that even professional law enforcement agents are very poor at recognizing liars, and scientists and engineers across the country are trying to give them a mechanical helpmate that can detect even tiny and incredibly brief clues that a person is less than truthful.
It's called "Avatar," not to be confused with the movie by the same name. Avatar looks like an "ATM on steroids," according to Doug Derrick, a researcher at the University of Arizona who is helping develop a machine that may someday ask what you really have in your bag. If it thinks you are lying, it will signal a real person to step in and pick up the interrogation because a twitch in a tiny facial muscle aroused suspicion.
At least that's what scores of researchers at 14 leading institutions across the country are hoping will happen. They are part of an ambitious multi-disciplinary effort to bring high technology to border patrols and airport screenings.
A consortium called "BORDERS," sponsored by the Department of Homeland Security and headquartered at the University of Arizona in Tucson, is focusing attention on everything from bureaucracies to sophisticated sensors to move security into the 21st century.
Avatar is rapidly becoming the poster child of the program, although it is only one of many projects. It's a kiosk with a computer screen that will show an animated representation of a border agent, and it will ask a series of questions to see if there is any reason for concern about some chap trying to cross the border from Mexico or Canada.
The idea behind it has gained momentum as various labs have zeroed in on how the human face, or body, changes if a person is lying. For example, researchers at the Mayo Clinic in Rochester, Minn., found that lying sends excessive blood flowing to certain areas of the face, and they could detect that about 80 percent of the time with thermal imaging technology.
Other researchers at Temple University Hospital in Philadelphia used brain imaging equipment to show that parts of the brain light up when a person lies. Computer scientists at Rutgers University used sensors to identify certain body movements that indicate a person is lying. These are largely beyond our control.
"There are about 300 different cues that people have identified that may indicate deception," Arizona's Derrick said in a telephone interview. "Our research is focused on trying to get 12 to 15 reliable cues that measure deception. A person may be able to control some of the cues, maybe three to five of them, but other cues will leak out no matter what the person does."
One tell-tale cue is dilation of the pupil. The researchers find that lying causes the pupil to dilate within about three seconds if you tell a lie.
"It's very quick, and very small, and it happens almost immediately," Derrick said. A human agent is not likely to detect that brief signal, but Avatar can. Of course, many things can cause the eye to dilate, even the setting sun, but in this case, the rapid dilation and quick resumption of normal size is a clear signature of lying. And that should be augmented by other cues, like a change in the pitch of the person's voice, or twitching of a particular facial muscle.