From VOA Learning English, this is the Health & Lifestyle report.

What is the best way to catch someone who is telling a lie?

For a long time, the traditional method of identifying liars was to watch their body language, including facial expressions.

What if the person appears to be nervous? Is the person unable to look me in the eye? Is he or she looking around the room? What about other nervous movements, such as fidgeting or shifting from side to side?

Many people – from parents to police officers and airport security personnel – depend on this method. But does a person's body and face reveal the truth?

Not according to a new study.

Talking, it seems, is the best way to smoke out a liar. That is what researchers in the United Kingdom found out recently. Their investigation took place at one place where lying can get you into big trouble – an airport.

The researchers asked volunteers to pretend they were real passengers and then lie to airport security agents. Some of the agents used spoken conversation-based methods to question these make-believe passengers. Others depended instead on the person's body language, like lack of eye contact and showing signs of nervousness.

The agents talking with the passengers were 20 times more likely to catch the liars. The study found that these conversation-based techniques can help you recognize when a person is lying to you.

Like many methods, this conversation method has a name. It is called Controlled Cognitive Engagement or CCE, for short.

The British government partly financed this study. The American Psychological Association published the findings.

Body language cannot be trusted

Using body language and facial expressions to catch someone in a lie is really hard. And it only works, seemingly, by chance.

Thomas Ormerod is the head of the School of Psychology at the University of Sussex in England. On the APA website, he reported that the "suspicious-signs method" -- or using body language – "almost completely fails" in finding lies.

In the conversational CCE method, security agents just talk with passengers. They ask about informal things as you would in a normal conversation. While talking, the agents might ask questions about topics that are seemingly unrelated. Then the agent observes if the person becomes more evasive or erratic. They also observe is their way of speaking changes.

In an article on the APA website, Ormerod says that for actual passengers, they are "just chatting about themselves. It shouldn't feel like an interrogation."

Here are four ways of catching a liar.

1. Use open-ended questions

These are the opposite of "Yes" and "No" questions. Open-ended questions force the person to stretch the story of their lies until they caught in their own web of lies.

2. Use the element of surprise

Ask questions they may not think you are going to ask. Ask questions that are surprising or off-topic. This will make it harder for them to keep lying. Or better still ask them to re-tell an event backwards in time, going from the most recent event to the earliest. This is hard enough to do with the truth, let alone a story of lies.

3. Look for small details that do not add up or, in other words, make sense.

Ask them details about their story and look for facts that seem in disagreement with each other. But do not let them know you know. Just let them dig themselves deeper into a hole.

4. Watch for changes in confidence and speaking styles

Liars will often change their speaking style when they are questioned. For example, when they feel in control they may be very talkative. But if they feel they are losing control, they may not talk much at all.

And that's the Health & Lifestyle report. I'm Anna Matteo.

You can trust me.