This article was taken from the April 2011 issue of Wired magazine. Be the first to read Wired's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online.

They may rely on dubious "science", but lie-detector tests are used to settle relationship disputes and are common in US criminal cases. So if you're forced to take one, it's worth knowing ways to sail through. George Maschke, cofounder of antipolygraph.org, explains how.

You don't need to take the test


"The best course of action is to refuse," says Maschke. "It's demeaning and you should feel insulted." The law is on your side:

UK courts don't accept evidence gathered by polygraph tests. But this won't help you if it's an untrusting spouse demanding you take the test to settle an argument.

Know how the test works

A polygrapher asks three types of questions -- "relevant", "irrelevant" and "control". He will compare your physiological reactions, such as heart rate,to each. If you show a stronger response to relevant questions ("Have you cheated on your wife?") than controls, he'll infer lying.


Become a control freak

"Understand which are the control questions and you can covertly augment your physiological reactions," Maschke says. So, look out for questions everyone would be expected to lie to. "For example,

'If you're an honest person you would never have lied to someone who's loved you, would you?'"

Create stress with maths

Now you can skew your response for a false reading. "It has to be something that cannot be detected," says Maschke. "You could constrict the sphincter, but many operators put sensors on the seat." So, the best method is to try to solve a maths problem in your head as quickly as possible in order to create stress.

Look them in the eye


Remember that other cues might be monitored. "Make eye contact, but don't stare down the operator," says Maschke. Although not all polygraphers take into account body language -- "Some say you should only go by the chart and nothing else," he says -- it's better to be safe than sorry, right?

Forget spy games

Eschew the pulp-novel method of spraying antiperspirant on your fingers. "The method is not to suppress all sweating, but to sweat more on control questions," says Maschke. He also advises against putting drawing pins in your shoe to cause stress, as some polygraphers have pads to pick up on that.