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Why do kids lie?

This is a question on every parents mind. There is some interesting research behind kids and lying.

First, let’s look at where kid’s lies come from:

  • Very young children (under 5) are not able to consistently distinguish between reality and their very rich imaginations. According to Michael Brody, M.D., a child psychiatrist in Potomac, Maryland, “Very young kids don’t know the difference between truth and fiction.”  Many of the tales they tell aren’t lies simply because they don’t know the difference.

I’m not sure if this little guy knows the difference or not, but it is certainly a fun example of what lying looks like at this age.

  • Older children most often lie to avoid unpleasant tasks or trouble.  With these types of lies, it is important to understand the reason behind the lie and focus on that rather than fixating on the lie itself.  My own daughter lied when she was little about having headaches because she liked the flavor of the medicine.  When I figured out what was happening, the most important thing was to talk about how dangerous it is to take medication we don’t need.
  • If they are lying to avoid unpleasant tasks like homework or cleaning up a mess, it is better to work together to find ways to get the job done, than to get into a showdown about the truth. If we focus on punishing for the lie, we think we are teaching “lying is bad” but often times what is heard is “getting caught is bad.”
  • Lastly, children lie because they don’t want to disappoint us. So the question to ask is “How do I help my child feel they are good enough just as they are?” It is important to separate out your own wants and desires from your children’s so that they are comfortable telling you the truth.

But what if my children tell me something I don’t want to know?

That leads us to the next step in building a culture of honesty, modeling willingness to have difficult conversations with your children. If you truly promote honest conversations, uncomfortable topics are going to come up. At various honest times in my house, I’ve been vulnerable, unpopular, wrong, hurt, uncertain, overly certain, tough, tender, forgiving, and everything in between. This parenting stuff is not for the faint of heart.  

Lastly, don’t discount the power of modeling honesty.  

This research from “Lying in Everyday Life” by DePaulo, Kashy, Kirkendol, Wyer, & Epstein in the Journal of Personality and Social Psychology:

“Consistent with the view of lying as an everyday social interaction process, participants said that they did not regard their lies as serious and did not plan them much or worry about being caught. Still, social interactions in which lies were told were less pleasant and less intimate than those in which no lies were told.

If you have a kid who lies, what do you do? How do you know when your child or teen is telling you the truth? Being able to decipher truth from fiction is incredibly important for parents as teens especially can be complicated.

The clues below are some of the statistical signs of deceit — meaning they most often show up in people who are lying. Lie detection and body language is a complex science, but I have simplified it here for immediate application.

The most important thing to remember about lie detection is that one clue alone does not guarantee lying — if you see some of the clues listed below, it is simply a red flag to get more information.

1. Verbal Nuance

If the timing is off between gestures and words, lying or hidden emotions are most likely lurking. For example, if your teenager is talking about how angry they are about something, but their facial expression is one of sadness or neutrality, they are most likely forcing the emotion even though they do not feel it. Verbal nuance can also show up as a delayed reaction to the emotion. They might say, “Yeah, I am angry about it,” pause and then display an angry expression. This is not genuine emotion because their words are not matching their expressions.

2. Relief

A liar almost always shows great relief when the subject is changed. If you are talking to your teen about an issue you are suspicious of and then move on from the topic, notice their reaction. If they show great relief or a total change in behavior, they were most likely tense or hiding something.

3. Fear vs. Surprise

In my presentations and articles on nonverbal behavior, I often reference microexpressions. A microexpression is a brief, involuntary facial expression that is shown on the face of humans according to the emotions that are being experienced. Unlike regular prolonged facial expressions, it is difficult to fake a microexpression. They often occur as fast as 1/15 to 1/25 of a second. There are seven universal microexpressions: disgust, anger, fear, sadness, happiness, surprise and contempt. In terms of lying, I believe that fear and surprise are the most important ones for parents to recognize. After all, if you ask your child, “Did you know about the cheating incident at school?” A fearful microexpression will tell you something very different than if they look surprised.


  • The brows are raised and curved
  • Skin below the brow is stretched
  • Horizontal wrinkles across the forehead
  • Eyelids are opened, white of the eye showing above and below
  • Jaw drops open and teeth are parted but there is not tension or stretching of the mouth


  • Brows are raised and drawn together, usually in a flat line
  • Wrinkles in the forehead are in the center between the brows, not across
  • Upper eyelid is raised, but the lower lid is tense and drawn up
  • Upper eye has white showing, but not the lower white
  • Mouth is open and lips are slightly tensed or stretched and drawn back

4. Verbal Clues

If you are speaking with your child and they begin responding to an accusation by offering a belief in general instead of the specific instance (i.e. ‘Do you smoke pot?’ ‘I believe pot is dangerous’) they are subconsciously avoiding answering the question. They also might add in additional details until you believe them to fill silences. Liars often use phrases like “to tell you the truth,” “to be perfectly honest,” and “why would I lie to you?” Another clue to deceit is when teenagers have answers that sound extremely rehearsed, even if it is about a casual event.

Lying is a very natural, yet worrisome occurrence. Unfortunately it is part of growing up, but parents need to be aware of teens lying habits to keep them safe. I share these tips and hope they will be used in the right circumstance.

Want some more lying tips? Check out:

The Ultimate Guide on How to Tell if Someone is Lying

How to Tell if Someone is Lying Over Text: 5 Red Flags

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