How to catch a liar (it's harder than you think)How to catch a liar (it's harder than you think)
All In The Mind
Rebecca figured out a brilliant way to catch her partner in a lie. It led to a career in forensic psychology… These days, Rebecca studies lie detection, and it turns out, people generally overestimate their ability to tell fact from fiction. All the classic clues — body language, eye contact, acting nervous … they don't really hold up when put to the test. In our fourth and final part of our special series, Forensic, we're discovering the truth about lie detection. Are there any giveaways that someone is lying to us? Can lying show up on a brain scan? If you've enjoyed Forensic, please leave us a review or share the show with a friend. And don't forget to send us your questions based on the series, you can reach us at allinthemind@abc.net.au Guests: Dr Rebecca Wilcoxson Lecturer in Forensic and Social Psychology, CQ University Dr Arthur Lee Assistant Professor, Boston University Credits: Presenter/producer: Sana Qadar Senior producer: James Bullen Producer: Rose Kerr Sound engineer: Roi Huberman You can catch up on more episodes of the All in the Mind podcast with journalist and presenter Sana Qadar, exploring the psychology of topics like stress, memory, communication and relationships on ABC Listen or wherever you get your podcasts.
35:10•29 May 2026
How Bad Are We at Spotting Liars?
Episode Overview
- Common beliefs about liars—like avoiding eye contact or fidgeting—are not reliable indicators of deception.
- People across ages and backgrounds strongly overrate their ability to spot liars, yet perform only slightly better than chance.
- Those most anxious or visibly nervous are often the least likely to be guilty, while confident offenders can appear very convincing.
- Brain-based lie detectors can look accurate in the lab but may really be measuring other states, such as selfishness, creating dangerous false positives.
- Judging credibility by demeanour alone, as shown by the Lindy Chamberlain case, can contribute to serious miscarriages of justice.
“There is no one behaviour that will reliably predict lying.”
Curious about how others navigate their sobriety journey? This time the focus is on lies, truth, and how often our instincts get it wrong. Fans of psychology, true crime, and anyone who thinks they’re a “human lie detector” will find plenty to chew on. The episode follows forensic psychologist Dr Rebecca Wilcoxson, whose interest in lying started with a cheeky trick on a dishonest boyfriend.
By simply telling him, “you do something with your face when you’re lying,” she spooked him into freezing his expression whenever he bent the truth. It’s a funny story, but it sets up a serious message: classic clues like shifty eyes, fidgeting and nervous body language are a terrible way to judge honesty. Rebecca explains how these myths feed straight into policing and jury decisions, with heartbreaking consequences.
The Lindy Chamberlain case is used as a clear warning: people assumed guilt because Lindy didn’t behave like the grieving mother they expected, and that misreading of emotion helped send an innocent woman to prison. Neuroscientist Arthur Lee then takes things into the brain scanner, sharing research on whether brain activity can reveal deception. His team built a lab-based “lie detector” that seemed pretty accurate—until they realised it was also picking up selfishness rather than pure lying.
As he puts it, high accuracy means very little if you’re measuring the wrong thing. Along the way, you’ll hear why humans are so bad at spotting lies (we’re barely better than a coin flip), why polite “white lies” might actually keep society running, and why a truly reliable lie detector is still a long way off. If you’ve ever judged someone’s honesty by their body language, this conversation might make you think twice before calling anyone a liar again.
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