Some teachers and parents seem to have an uncanny ability to see through a lie, but they can never really know for certain, that would involve mind-reading!
A polygraph machine can’t mind-read either, but it has become known as a ‘lie detector’ because it is pretty good at picking up on the telltale signs of tall tales!
Ask No Questions, Hear No Lies. If you tell a lie you’ll probably feel a bit nervous about it. If it’s a real whopper, your heart might start to pound and you might get a bit hot and sweaty. A polygraph machine is a device that monitors changes in the body that are associated with telling lies, such as blood pressure, heart rate, how sweaty you are and how fast you’re breathing. These results are analyzed.
US psychologist William M. Marston invented an early type of polygraph that measured blood pressure and was used in the First World War to question prisoners. Another psychologist, John A. Larson, invented a more modern type of polygraph in 1921 that was able to measure changes in a person’s breathing and pulse rate too.
Leonard Keeler, who worked with Larson, made further improvements in 1938 by adding a psychogalvanometer, a device that measures activity in the sweat glands.
But what if you’re anxious, hot and sweaty for other reasons? Just the thought of taking a lie-detector test might worry you. Or what if you’re really good at covering up stress? And polygraph results can be interpreted in different ways by different examiners. For these sorts of reasons, polygraphs are not foolproof and they can’t be used as evidence in a law court in the UK.
Wonder Man: William Marston, one of the inventors of the polygraph, also created the cartoon character Wonder Woman under his pen name Charles Moulton. Wonder Woman had a Lasso of Truth that forced anyone caught in it to be honest.
IT’S ALL LIES. They may be little white ones or massive whoppers, but the long and short of it is that everyone tells porky pies, although some people are better at lying than others. Use the tips below to try to catch someone out and uncover their web of deceit.
HOW TO SPOT A WHOPPER. It’s impossible, unless you’re a mind-reader, to know for certain if someone is telling the truth or lying, but here are some things to look out for which might give the game away:
Are they avoiding eye contact or making too much deliberate eye contact?
Are they touching their face and hands more than usual?
Do they appear nervous – for example, fidgeting a lot and looking uncomfortable?
Are they slow to answer questions (perhaps stalling for time to invent their story)?
Are they avoiding giving details, or including an unusual amount of detail?
Is their story inconsistent? Do they change certain details under intense questioning?
Are they accusing you or someone else in order to cover up or deflect their lies?
Are they refusing to answer your questions or trying to change the subject?
YOU LIAR! Name and shame the biggest liar you know! Who among your family and friends lies the most? What is the worst lie they’ve told? How good at lying are they? How many times have you caught them lying? How good at lying are YOU? Did you get found out? Did you get into trouble?