It might come as a surprise to daytime TV viewers - "We've proved your husband was cheating!" - but polygraphs aren't actually that accurate.
Now, though, a group of University of Utah researchers have developed an alternative based on tracking eye movements that they say is already at least as good.
They've licensed the technology to Credibility Assessment Technologies (CAT).
"The eye-tracking method for detecting lies has great potential,"
says CAT chairman Gerald Sanders. "It’s a matter of national security that our government agencies have the best and most advanced methods for detecting truth from fiction, and we believe we are addressing that need by licensing the extraordinary research done at the University of Utah."
Unlike the polygraph, which measures a person’s emotional reaction to lying, eye-tracking technology measures the person’s cognitive reaction.
Researchers record a number of measurements while a subject answers a series of true-and-false questions on a computer. The measurements include pupil dilation, response time, reading and rereading time, and errors.
Lying requires more work than telling the truth, so the researchers look for indications that the subject is working hard. For example, a person who is being dishonest may have dilated pupils and take longer to read and answer the questions.
These reactions are often minute and require sophisticated measurement and statistical modeling to determine their significance.
"We have gotten great results from our experiments," says educational psychologist John Kircher.
"They are as good as or better than the polygraph, and we are still in the early stages of this innovative new method to determine if someone is trying to deceive you."
Besides measuring a different type of response, eye-tracking methods for detecting lies has several other benefits over the polygraph. It promises to cost substantially less and require one-fifth of the time currently needed for examinations, and can be administered by technicians rather than qualified polygraph examiners.
The researchers hope the technology will be taken up by government agencies, which regularly use polygraphs to screen employees and applicants for sensitive positions.
"It’s exciting," says researcher Anne Cook, "that our testing method is going to be taken from a basic research program to commercial use."