When a teenager lies: what lies beneath

“I was at Nika’s. We were revising for physics.”

Her mum nods. Half an hour earlier, on her younger son’s phone, which he had left on the sofa, she happened to see a post: her daughter with friends on a bench in the park, with a bag that did not contain any physics. Now she is standing in the kitchen with both truths in her head, feeling something she cannot untangle. Is she angry because her daughter lied to her? Frightened, because she does not know what was in the bag? Or hurt, because she thought they were closer than that?

When a parent first properly catches a teenager in a lie, it is often not only their trust in the child that is shaken, but also their trust in themselves as a parent. In this post I want to write about why teenagers lie, what a lie often says about the relationship, and how to respond so that next time it is easier to tell the truth — rather than easier to lie better.

A lie is not only a moral question

When we discover a lie, we first read it morally: lying is wrong. That is true, and the teenager knows it. But if we stop there, we miss what the lie was for. In adolescence a lie is very often not an attack on the parent, but a clumsy, sometimes dangerous tool for something developmentally typical of this stage: carving out a space of one’s own.

The researcher Judith Smetana and her colleagues have shown that teenagers divide their lives into fairly clear areas. Some, in their view, rightly fall under their parents’ authority — safety, school, household agreements. Others, such as friendships, crushes, music, clothes and what they think, they experience as their own. About these areas they more often tell their parents nothing, or only part of the story. This is not rebellion, but a sense that “this is none of your business”.

That line shifts as a child grows up, and it has to. The problem arises when a teenager and a parent cannot talk about where it lies — and when the teenager judges that the truth will trigger a reaction they will not be able to handle. Then a lie is a shortcut.

How many teenagers lie to their parents

If the lie surprised you, it helps to know how common it is. In a study by the psychologist Lene Jensen, Jeffrey Arnett and colleagues, more than four in five secondary school students said they had lied to their parents about at least one thing in the past year. Most often about friends, where they had been, dates, parties, alcohol and money. Interestingly, most of them also felt that lying to parents was wrong. So the lie was not a sign that they did not care, but that they were weighing two things that both mattered to them.

That does not make lying unimportant. But it does mean that a single lie from a teenager is more the rule than a sign that something is badly wrong with your child or with you. More important than whether they lie is the question of what about and why.

Four reasons a teenager lies

Lies differ a great deal from one another, and a response that is right for one is wrong for another. Broadly speaking, four reasons come up most often.

Avoiding a penalty. This is the best-known reason and also the simplest. The teenager judges that the truth will bring punishment, shouting or long-lasting disappointment, and chooses to lie. What matters here is not only how strict the consequence is, but how unpredictable. If a teenager does not know whether a parent will just sigh at bad news or explode, a lie is the safer bet.

Keeping something for themselves. These are lies about areas the teenager experiences as their own. They do not say who they are messaging, what happened between their friends, who they have a crush on. Often this is not invention but omission — the story is true, only an important part is missing.

Protecting someone. Teenagers often lie because of others: so as not to give away a friend, not to get a brother or sister into trouble — or to protect a parent. That last one is less obvious, but not rare. If a teenager knows that Mum is already at the edge, or that Dad shuts down at bad news, a lie can feel to them like consideration.

Hiding shame. Some lies are not aimed at the parent, but at the teenager themselves. A bad grade they do not mention is not necessarily hidden out of fear of punishment, but because they are ashamed, because they cannot look in the face of something that has disappointed them. This reason is often overlooked, because on the outside the teenager seems not to care. There is more about how shame works in the entry shame and in Guilt and shame are not the same — and the difference matters.

What parents actually know — and how

When we discover a lie, we often respond with tighter control: checking the phone, the location, calling friends. That is understandable. But one of the most cited studies in this area suggests that control does not work the way we imagine.

The Swedish researchers Margaret Kerr and Håkan Stattin looked at where parents’ knowledge about what their teenagers do actually comes from. They found that most of what parents know does not come from their checking and supervision, but from what the teenager tells them of their own accord. And teenagers tell their parents more when they experience the relationship as warm and when they do not expect every piece of information to be used against them. It was this voluntary telling that was most strongly linked to young people getting less involved in risky behaviour.

This does not mean supervision is never needed. But it does mean things can very quickly spin into a loop nobody wants: more control means less telling, less telling means the parent knows less, which makes them more afraid — and they increase control.

A study by Catrin Finkenauer and colleagues adds a further nuance. On the one hand, keeping secrets from parents in adolescence is linked to a greater sense of independence — which makes developmental sense. On the other hand, teenagers who kept more secrets from their parents were on average more low in mood, more stressed, and reported more physical complaints. So a secret is not only a wall against parents. It is also a weight the teenager carries alone.

What to do the moment you discover a lie

The first reaction is almost always the least considered. That is human. But because the first reaction is the one the teenager will remember, and by which they will weigh next time whether to tell the truth, it is worth preparing for it at least a little.

• Don’t set traps. If you already know what happened, don’t ask as if you didn’t, to see whether they will lie. That pushes them into a lie you then punish. Say what you know.
• Separate two things. One is what they were hiding (the park, the bag, being late). The other is the lie itself. Both need talking about, but not in the same sentence and not with the same anger.
• Safety first. If the lie is hiding something dangerous, that comes first. The conversation about trust can wait until tomorrow.
• Give yourself time. “I’m too angry to talk right now. We’ll sit down tomorrow after lunch.” That is not weakness. It is an example of how to handle a strong feeling.
• Don’t generalise. “You never tell the truth” tells a teenager they are a liar. People often behave in line with what others think of them.

What the conversation sounds like

This is how a conversation might sound the next day, once the anger has eased a little (composite, not a real person):

Mum: “Yesterday I saw a post from the park. I know you weren’t at Nika’s.”
Daughter: “I was. For a bit.”
Mum: “We’re not going to argue about that. I’m more interested in why you decided not to tell me.”
Daughter: “Because you’d have said no.”
Mum: “Maybe I would. Maybe we’d also have agreed on a time. Now I don’t know where you are when I think I know — and that scares me more than the park.”
Daughter: “… It wasn’t anything bad.”
Mum: “I believe that it seems that way to you. Tell me what happened.”

Mum did not say the lie was fine. She said what she finds hardest about it — that she does not know where her daughter is — and asked for the reason instead of announcing it herself. A consequence may still follow. But the conversation stayed open.

Exercise: an agreement about the truth

This exercise is for parents whose trust has been shaken by a lie and who want to do more than just tighten the rules. You can start it today.

1. Write down what you need to know, not what you would like to know. Where they are, who with, when they will be home, how they will get home. Separately, write down what you would like to know but is not essential — what they talk about with friends, what they think. The first list is an agreement; the second is an invitation.
2. Tell your teenager which part is non-negotiable and why. Briefly and without a lecture: “I need to know where you are, because I’m responsible for you. Not because I don’t trust you.”
3. Agree on a discount for honesty. If they get into a mess and tell you themselves, the consequence is smaller than if it comes out some other way. And the agreement holds — even when the news is genuinely unpleasant.
4. Introduce a safe call. If they are ever somewhere they don’t feel safe, they can call or send an agreed word and you will come and get them — no questions that evening. There will be a conversation later, but it will not be a punishment for calling.
5. Check in after two weeks. Not only whether your teenager kept the agreement, but whether you did. Was the consequence really smaller when they told you themselves?

The exercise is demanding mostly for the parent. It asks you to bear a truth you would rather not hear and to stay calm alongside it. But that is exactly the condition for the truth to arrive at all. Trust is not built on promises, but on the experience that it was safe to tell.

What a lie says about the family

In relational family therapy, which I am training in, when it comes to lying we are interested not only in the teenager but also in the atmosphere in which lying came to make sense. Christian Gostečnik describes how families often repeat patterns that nobody chooses consciously — including patterns around truth and secrets.

Here are a few questions worth asking, without blaming yourself. What happens in our home when someone brings bad news? Do the adults in the family tell each other the truth — about money, about health, about how things are going between us? Has the teenager learned that some topics are off limits at home? Children do not learn about honesty from the rule “don’t lie”, but from what they see. If there are stories in the family that nobody talks about, a teenager quickly understands that silence is a way of surviving. I wrote about how secrets pass between generations in Family secrets and unfinished stories: where a genogram finds them.

A lie can also say something about boundaries. If boundaries at home are so loose that there are none, or so rigid that there is no room in them to grow up, lying is often a teenager’s way of getting the space nobody gives them. How to set boundaries that hold while keeping the connection is covered in How to set boundaries with a teenager without losing your connection, and you will find a short explanation in the entry boundaries.

If conversations at home keep going round the same loop of lying, discovery and punishment, family therapy can help — there we all talk together, and the teenager has room to tell their side too. How this works when a teenager does not want to talk at first is something I described in When a teenager goes quiet: how family therapy opens the conversation.

Where this approach falls short

Everything I have written applies to lies that are part of ordinary growing up. But there are circumstances in which understanding and agreements are not enough and you need to act differently.

• When the lie hides substances. Alcohol and drugs are among the most common topics teenagers lie about. Occasional experimenting is different from regular use; more about when it is time to worry in Alcohol and drugs in the teenage years: when it is time to worry.
• When the lie hides food, the body or injuries. Hiding eating, excuses that they have already eaten, long sleeves in summer — these can be signs of distress that need a doctor. See Early signs of an eating disorder in a teenager — what to notice before it gets bad.
• When an adult is involved. If a teenager is hiding contact with someone considerably older, especially online, or changes after that contact, this is not a question of privacy but of safety. If you suspect violence or abuse, call the police on 113 in Slovenia or the SOS helpline on 080 11 55 in Slovenia.
• When they lie about everything, all the time, for no obvious reason. Lying that is not connected to anything the teenager would want to protect, or that comes with other behavioural difficulties, is a reason to talk to a specialist in children and adolescents.

For the teenager themselves, the first doors are the family doctor or paediatrician, the school counselling service, or a therapist who works with children and adolescents. In Slovenia, young people can call the TOM helpline free and anonymously on 116 111. If a teenager talks about suicide or is self-harming, call the crisis line Klic v duševni stiski on 01 520 99 00 in Slovenia (7 pm to 7 am) or the Samaritan helpline on 116 123 in Slovenia (24 hours a day), and in an emergency 112.

What to remember

• Most teenagers lie to their parents at some point; more important than whether they lie is what about and why.
• The most common reasons are avoiding a penalty, guarding their own space, protecting someone, and shame — and each calls for a different response.
• Parents know most from what a teenager tells them of their own accord; tighter control without connection can reduce that telling.
• The truth arrives when it is safe: with predictable consequences and a calm response to bad news.
• When a lie hides danger, safety comes first, and the conversation about trust comes later.