Everyone has told a lie. From telling white lies and exaggerating to deceiving and compulsive lying, there are many reasons behind why people don't speak to the truth.
Astonishingly, it takes just five seconds to know if someone is fibbing.
Here, Sydney's behavioural expert Grazina Fechner reveals the signs to spot a liar - and how to confront them if you know they are telling porkies.
Speaking to The Morning Show, Ms Fechner said there are many red flags to look out for, including eye expressions because our eyes can give away if we're trying to hide something.
Face touching, fidgeting and voice pitch are good indicators that someone's being deceptive.
Ms Fechner said another way to spot a liar is when the person becomes defensive and their confidence diminishes.
She also explained people who lie, otherwise known as compulsive liars, all share similar personality traits.
'They ooze confidence because they genuinely think: "I do it all the time, I know what's going on",' she said.
'They think fast, they understand others and most of all they've got a great memory because they've got to remember what they said last time and the time before.
'They build on their story, and they become an actor because they do it all the time, so it's just their world - and they genuinely believe it.'
She said these types of people don't set out to deceive because they subconsciously believe their own lie.
'They genuinely walk away from an interaction, thinking it's happened or believing they've done it,' she said.
Before confronting a liar, Ms Fechner said it was important to consider your relationship, ask before accusing, have evidence and remain confident.
'If [the person] is really important to you, confront as early as you know. Make sure you confront in the right environment,' she said.
When you do have a case to confront the person, Ms Fechner said it was important to bring it up to them because it could affect your relationship if you don't.
'Otherwise it's going to fester and build up, and then you're not going to trust them, and then you're going to lose trust,' she said.
'And the relationship that was great is now just sliding down a hill all because you didn't confront them.'