Can you tell who’s lying?
After a stressful day, you come home to the last slice of cake that you’ve been looking forward to. You open the fridge, and it’s gone. Someone has taken it. You gather your family in the living room for the interrogation, and they all deny it.
Your father is sweating, your mother is fidgeting, your sister keeps adjusting her clothes, and your brother won’t make eye contact.
So – who’s lying?
Lies about lying
Myth: liars sweat more
This myth comes from the belief that people who are lying are stressed. This activates the fight-flight-freeze response, releasing adrenaline and activating sweat glands. It’s certainly true that people who are lying are stressed; but so are honest people being falsely accused. Or people could be sweating from something entirely different.
You realise your father has just come back from a run. Ok, next suspect.
Myth: liars fidget and groom themselves
Again, the idea that people are stressed when they lie. The excess adrenaline leaves a person feeling the need to move around and hence they fidget. And like sweating, people will fidget from the stress of lying or of being accused of lying.
Your mother is anxious about the pot she has left on the stove, and your sister is uncomfortable sitting in her new clothes that don’t fit right. Time for our last suspect.
Myth: liars avoid eye contact
This originates from the opinion that people feel guilty about their lies and can’t bring themselves to maintain eye contact. However, plenty of people can easily look someone in the eye and lie. There is also an idea that people will look right when lying and left when telling the truth; this also has no scientific evidence.
Not only is it inaccurate, but this idea can also be harmful. Autistic and other neurodivergent people often struggle to maintain eye contact, and this myth that people avoid eye contact when lying perpetuates the incorrect stereotype that people on the autism spectrum are dishonest or apathetic.
You realise your brother is watching footy game on the television behind you. What now?
How to spot a lie with science
Most people are aware of these aforementioned myths, and will actually go out of their way to avoid doing them. When you ask a guilty person where they were last night, they may sit very still and look you straight in the eyes. An innocent person hoping you’ll believe them may do the exact same thing.
And it is important that this is understood. In 1990 for two separate crimes, 17-year-old Martin Tankleff was “too calm” after his parents’ murders, and 16-year-old Jeffrey Deskovic was “too distraught” after his classmate was found dead. Both were innocent, but their behaviour was considered guilty, and they served over 15 years each in prison before being exonerated.
Ultimately experts have accepted that there really is no concrete, one-size-fits-all method to detecting a lie.
But wait, who stole the slice of cake?
Your grandmother walks into the room with a smear of frosting on her lip asking what the fuss is all about. Sometimes the truth isn’t hard to find; you just need to look.