Teenage offenders are highly adept at spotting when their peers are lying

Most people are poor at detecting whether someone is lying, at least partly because most people think mistakenly that things like shifty eye movements and fidgeting hands are reliable signs of deception.

However, it's emerged in recent years that not everyone is equally bad at lie detection. In fact, people who themselves are skilled at lying tend to have quite a knack for spotting when someone else is telling a fib. Now a study published in Applied Cognitive Psychology makes a similar observation in teenagers. Teens with a record of criminal activity showed an enhanced ability to detect whether their peers were lying.

Louise Jupe and her colleagues at the University of Portsmouth recruited 16 teenage offenders – their average age was 15, and 8 of them were female – who'd committed a range of crimes including battery, theft, racial assault, arson and criminal damage; and a control group of 36 teenagers with no record of criminality and with an average age of 16 (and 24 of whom were female).

The participants watched 12 video clips, between 78 to 90 seconds in duration, of teenagers aged 14 to 18 answering questions about whether or not they were concealing in their clothing a digital music player. The participants' task was simply to say whether they thought each of these teenagers was lying or not, and at the end to say what behavioural cues they'd used to make their judgments.

The researchers had recorded the video clips earlier with 12 teenagers who were not participants in the study. Half of the videoed teenagers were given a digital music player to hide in their clothing, and they were instructed to lie and say they didn't have the device. The other half were not given the music player and they were told to tell the truth about not having it.

The participants with no record of criminality were hopeless at telling whether the teens in the videos were lying or telling the truth – in fact, they achieved an average of 50 per cent correct judgments, which is no better than if they'd just guessed. In contrast, the teenage offender participants managed an overall accuracy rate of 67 per cent (they accurately identified 60 per cent of truth tellers and 73 per cent of liars).

This the first time that lie detection abilities have been studied in teenage offenders, and the result extends to the teenage age group the earlier observation that adult prison inmates are more skilled than average at lie detection. The authors of the current research believe that the superior lie detection abilities of teen offenders (and adults) likely comes from the fact that they've had practice at lying in interrogation situations, which has given them insight into the "tells" that reveal when someone is not being honest.

Intriguingly, however, the behavioural cue that the teen offenders said they used to spot lying (shifty eyes) was not actually displayed by the liars in the videos – making this just the latest study to debunk the popular misconception that lying is revealed in the eyes. Rather, the main tell-tale behaviour shown by the liars was keeping their hands and feet unusually still, which wasn't mentioned as a give away by the teen offenders. The researchers think this suggests that the teen offenders' lie detection ability is based on intuition and on automatic cognitive processes that they can't easily describe to others.

Apart from the small sample size, it's worth noting that this study, like much research in this area, has some weaknesses that make it unrealistic. For example, the lies were inconsequential and the participants couldn't interact with the teens in the videos. However, both these facts would likely make lie detection more difficult for the participants, so the teen offenders' deception detection ability might be even more impressive in real life.

Further reading

Jupe, L., Akehurst, L., Vernham, Z., & Allen, J. (2016). Teenage Offenders' Ability to Detect Deception in Their Peers Applied Cognitive Psychology DOI: 10.1002/acp.3214