How to tell if someone is lying to you, according to a psychologist - and why avoiding your gaze does NOT mean they're bluffing

If you think you can spot a liar from a mile away, you're probably getting it wrong.

A psychologist has revealed that many of the classic signs we associate with lying – for example a shifty glance or nervous fidget – could be completely innocent.

Dr Sasha Hall, a Senior Educational Psychologist working with Live Casinos, says people are often far too quick to treat individual behaviours as evidence that someone is bluffing.

'People often rely on popular ideas about body language, such as avoiding eye contact or fidgeting, but these behaviours can occur for many different reasons,' she said.

'Someone might be tired, anxious, distracted or simply thinking carefully about their answer.'

The same goes for touching their face or constantly shifting position.

The best way to spot a bluff, she said, is to keep an eye out for changes in their usual behaviour.

Dr Sasha Hall said that someone averting their gaze is not necessarily a sign that they're telling fibs (stock image)

Rather than hunting for a single giveaway gesture, Dr Hall says the more reliable signal is a shift away from someone's own normal communication style.

'When people think about bluffing, they picture someone with a completely blank face,' she said. 'In reality it's far more nuanced than that.

'Everyone has their own natural communication style — some people are highly expressive, others are far more reserved, and neither is inherently more convincing.

'What actually gives people away is a change from their own baseline.'

For example, a normally fast talker who suddenly slows down around a particular question may be worth paying closer attention to.

Likewise, someone who usually gives concise answers but suddenly starts over-explaining could be behaving differently from their normal pattern.

A sudden drop in detail can also be notable if the person is usually very forthcoming.

The same principle applies to how animated someone is, with an expressive person suddenly becoming unusually restrained potentially standing out.

A previous study found only 1 per cent of people tell 15 or more lies per day. This graph shows the frequency of daily lies for all participants over three months

Four signs someone is lying

1. Pace of speech: a normally fast talker suddenly slowing down, or a measured speaker starting to rush, particularly around a specific question or topic
2. Level of detail: sudden over-explaining, or a noticeable drop-off in how forthcoming someone is, relative to their usual pattern
3. How animated they are: an expressive person becoming unusually restrained, or a quiet person suddenly becoming animated
4. Engagement with others: becoming withdrawn, unusually attentive, or responding differently than usual when challenged

Alternatively, a normally quiet person who suddenly becomes much more animated could also be displaying a change from their baseline.

Changes in how someone engages with other people can also be revealing, such as becoming unusually withdrawn or attentive when challenged.

But even then, Dr Hall warns against treating any single behaviour as proof that somebody is lying.

Stress, tiredness, nerves and the subject being discussed can all cause perfectly honest people to behave differently.

The best approach is therefore to look for a pattern of changes in someone's behaviour, rather than trying to decode one suspicious-looking glance or twitch, she said.

Dr Hall pointed out that most of us are worse at spotting lies than we think.

'Most of us like to think we would know if somebody was lying to us,' she said.

'The evidence suggests we are generally not as accurate as we believe.'

The expert concluded: 'It is much more useful to understand a person's usual communication style before trying to interpret whether anything has changed.

'Without that context, it is very easy to read meaning into behaviours that may be entirely typical for that individual.'

Experts have previously revealed that you can tell someone is lying from their smile.

A real smile is seen in the eyes, while a fake smile is only in the mouth, Pamela Meyer, author of the book 'Liespotting', said.

She also said people should watch for a smile of contempt with one lip corner curled, as if the liar thinks he or she is getting away with something.

WHAT ARE THE NINE WAYS TO SPOT A LIAR?

The big pause: Lying is quite a complex process for the body and brain to deal with. First your brain produces the truth which it then has to suppress before inventing the lie and the performance of that lie. 

This often leads to a longer pause than normal before answering, plus a verbal stalling technique like ‘Why do you ask that?’ rather than a direct and open response.

The eye dart: Humans have more eye expressions than any other animal and our eyes can give away if we’re trying to hide something. 

When we look up to our left to think we’re often accessing recalled memory, but when our eyes roll up to our right we can be thinking more creatively. Also, the guilt of a lie often makes people use an eye contact cut-off gesture, such as looking down or away.

The lost breath: Bending the truth causes an instant stress response in most people, meaning the fight or flight mechanisms are activated. 

The mouth dries, the body sweats more, the pulse rate quickens and the rhythm of the breathing changes to shorter, shallower breaths that can often be both seen and heard.

Overcompensating: A liar will often over-perform, both speaking and gesticulating too much in a bid to be more convincing. These over the top body language rituals can involve too much eye contact (often without blinking!) and over-emphatic gesticulation.

The more someone gesticulates, the more likely it is they might be fibbing (stock image)

The poker face: Although some people prefer to employ the poker face, many assume less is more and almost shut down in terms of movement and eye contact when they’re being economical with the truth.

The face hide: When someone tells a lie they often suffer a strong desire to hide their face from their audience. This can lead to a partial cut-off gesture like the well-know nose touch or mouth-cover.

Self-comfort touches: The stress and discomfort of lying often produces gestures that are aimed at comforting the liar, such as rocking, hair-stroking or twiddling or playing with wedding rings. We all tend to use self-comfort gestures but this will increase dramatically when someone is fibbing.

Micro-gestures: These are very small gestures or facial expressions that can flash across the face so quickly they are difficult to see. Experts will often use filmed footage that is then slowed down to pick up on the true body language response emerging in the middle of the performed lie. 

The best time to spot these in real life is to look for the facial expression that occurs after the liar has finished speaking. The mouth might skew or the eyes roll in an instant give-away.

Heckling hands: The hardest body parts to act with are the hands or feet and liars often struggle to keep them on-message while they lie. 

When the gestures and the words are at odds it’s called incongruent gesticulation and it’s often the hands or feet that are telling the truth.