I recently noticed my 6-year-old son started lying. Not big lies but just denying everything, saying no, etc. How do I handle this situation?
okay first of all breathe 
a 6-year-old lying is so normal it is almost a developmental milestone. like genuinely, child psychologists talk about this. around ages 4-7 kids start figuring out that their thoughts are private and that other people do not automatically know everything they did. so the lying is kind of them testing that theory.
the thing that worked with my little cousin (I basically helped raise her) was not making the lie the main event. instead of going you are lying to me we would say something like I think maybe you are worried about getting in trouble. is that what happened? and she would almost always just… tell the truth after that. takes the pressure off.
it sounds small but the way you react to the first lie kind of sets the tone for whether they keep lying to you for the next ten years or not. no pressure 
Parent of three here, ages 5, 9, and 13. So I have done this rodeo at different levels 
The deny everything phase at age 6 is really common. What I noticed with my kids is that they lie most when they already expect to be in trouble. So the lying is kind of a defense reflex more than actual deception.
Two things that genuinely helped us:
First, we stopped asking questions we already knew the answers to. If I saw my son knock something over, I would not ask did you knock that over?because then I am basically setting up a lying opportunity. I would just say I saw what happened, let us clean it up together.
Second, we made a big deal out of truth-telling, not just punishing lying. Like when my kid told the truth about something hard, we would really acknowledge it. That was brave to tell me that. Thank you. Kids respond to that way more than you would think.
Oh man this thread. 
My son at 6 once told me with full eye contact, completely straight face, that he did not eat the piece of cake that was on the counter. The piece of cake that was still partially on his cheek. Like buddy. The evidence is literally on your face right now.
I had to turn away so he would not see me laughing before I figured out how to handle it.
What I did in that moment, and kind of what became our whole approach, was just stay really calm and not make it a big dramatic moment. I said something like the cake is already gone so that is fine, but I want you to be able to tell me things without worrying I will get really upset. And we kind of moved on.
The big dramatic reaction is actually what makes them lie more, not less. When they know a confession leads to a meltdown, they are going to keep their mouth shut every time. @NightIndex11, keep your cool even when it is hard and watch how much more they open up over time. 
Ah yes, the 6-year-old “I did not do it” era. A time-honored tradition passed down through generations of small humans who absolutely did do it
Look, I get the concern but the catastrophizing in these situations is usually way worse than the actual behavior. A kid saying “no I did not” when they clearly did is not a sign you are raising a pathological liar. It is a sign you have a normal 6-year-old with a developing brain.
That said, what actually works: do not corner them. Cornered kids lie harder. Give them a way out that does not feel like total defeat. Something like “I think maybe it was an accident, accidents happen” opens a door for them to tell the truth without it feeling like a full surrender.
Also MicroLauncher above made a really good point about not asking questions you already know the answer to. That one is underrated. Stop setting the trap and then being surprised when they fall into it.
Something worth thinking about that people do not always mention in these conversations: the lying is almost always about something underneath it.
At 6, kids do not lie for fun.That pattern usually means they are worried about a specific outcome. Getting in trouble, losing something they want to keep.
So the question worth asking yourself is what does my son think happens when he admits something? If the answer is he expects a really big reaction, that is where to start. Not by excusing the lying but by making the truth feel a little safer to say.
Also one thing I saw mentioned upthread that I want to second @ZenDelight’s point about naming the fear behind the lie is genuinely effective. 
Kids at 6 lying is basically just early-stage negotiations. They are learning what they can get away with, how adults respond, what the consequences are. It is annoying but it is also kind of impressive when you think about it? Little strategists.
The funniest part is always when the lie makes zero sense. My nephew once told me he did not break a toy that was literally in two pieces in his hands. At what point did he think this was going to work??
But genuinely, the calm approach is the right one. Kids who grow up in houses where admitting a mistake leads to a screaming match get very good at lying very fast. Kids who grow up knowing okay I messed up and told the truth and the world did not end tend to stay more open.
Welcome to the club that every parent joins around this exact age
My daughter went through a solid 4-month stretch where she denied things so confidently I started questioning my own memory. Did she actually eat that snack or did I imagine buying it? Was the marker on the wall there before? I genuinely do not know anymore.
What snapped me out of over-reacting was realizing I was turning every little thing into an interrogation scene. Like I was treating a 6-year-old like a suspect in a crime drama.
Calm down, pick your battles, and keep your reaction proportionate. Some stuff is just not worth the big energy. Save the serious talk for when it actually matters.
@NightIndex11, the fact that you are asking this calmly and thoughtfully already tells me you are probably handling it better than you think 
One thing that helped us a lot was reading with my kids about characters who told the truth even when it was hard, and then talking about it after. Not in a preachy way, just like why do you think he decided to tell the truth even though he was scared? Kids work things out through stories in a way they do not always do through direct conversation.
Also just normalizing mistakes in general helps. When I mess something up around the house I try to say it out loud. Oh I forgot to check the stove, my mistake. Seeing that adults admit things too and the world keeps spinning makes it feel less catastrophic for them to do the same.
It is a phase. Hang in there. 
Few things that are actually practical and not just be calm:
- Do not ask yes/no questions when you already know what happened. Did you do this is just an invitation to say no. Try tell me what happened instead.
- Have a clear and consistent consequence for lying that is separate from the original thing they lied about. This is important. If the punishment for lying is the same as the punishment for the actual offense, there is no incentive to come clean. But if telling the truth genuinely leads to a lighter outcome, they learn that fast.
- Catch them doing things right. This sounds cheesy but it works. When your son tells you something he could have easily hidden, make a note of it. Tell him you noticed. Kids repeat behaviors that get them positive attention way faster than behaviors that just avoid punishment.
None of this is an overnight fix but it adds up. Consistent approach over a few weeks usually shifts things noticeably. 
This thread is genuinely one of the better parenting discussions I have seen in a while, everyone brought something useful.
Just want to add one thing from my own experience as someone who lied a lot as a kid and can now look back on why, it was almost always because I expected the reaction to be bigger than the actual thing I did. The lie felt like the safer bet.
What changed it for me was one specific conversation with my dad where he found out about something I had been hiding and instead of getting angry he just said why did you think you could not tell me that? And I did not have a good answer. That question stuck with me.
So maybe try that sometime with your son. Not as a guilt trip but as a genuine question. It might tell you a lot about what he thinks will happen when he tells the truth, and that is really the thing to work on. 