Psychology can teach us how to tell if someone is lying. Talking to a liar can be an uncomfortable experience. You may have difficulty focusing on the conversion, instead wondering just how well you can trust them. Why do people lie is a broad topic and it could have lots of reasons, but signs of lying person are often universal.

Dr. Leanne ten Brinke of the Haas School of Business at the University of California has undertaken recent research that suggests humans have pre-set instincts for detecting liars, however, this is often overridden by our conscious minds.

Instead of relying on our underlying instincts, it’s possible to determine whether someone is telling the whole truth by keeping a lookout for a few key signs. In fact, research shows that learning about human lie detection can improve your ability to spot deception by up to 90%, which is a high increase when considering most humans are only 54% accurate when spotting lies according to the Science of People.

Ideally, you’ll already have a basic understanding of how the person in question usually acts in social situations. This shouldn’t be a problem if they are a friend or relative whom you regularly interact with. Dr. Lillian Glass, a behavioral analyst who has previously worked with the FBI to determine deception in suspects, suggests that once you understand a person’s normal behavior, it’s easier to pick up on uncharacteristic expressions, body language or attitude to the conversation.

 Body Signs Someone is Lying

1. Head Positioning Often Helps You Spot A Liar

You may notice the person make a sudden head movement when asked a direct question, such as a jerk, retraction or tilt. Glass explains in her book, ‘The Body Language of Liars’ that this often happens just before they would usually respond to the question.

2. Breathing Intensifies When Someone is Lying

Glass describes heavy breathing as a ‘reflex action’, commonly associated with lying. If you’re not close enough to hear or feel the individual’s breath, watch their shoulders, which will rise and listen to their voice, which may become shallow, unclear or cracked. Essentially, the person is experiencing breathlessness due to their increased heart rate and changes in their blood flow, which is caused by the pressure of lying. This also occurs when humans are nervous or tense.