Parents may ask you if their child’s recent lie predicts a lifelong pattern of dishonesty or a serious character flaw. Many parents will firmly demand and tell their children: "Don’t ever lie to me!" Although well meaning, such pronouncements may not achieve the desired result and could potentially do more harm than good.

Sometimes lies, no matter how small, are very disturbing to parents. But pediatricians should counsel them not to overreact. Try to help parents understand that a lie is often a reasonable solution to a problem for the child or adolescent. Also assure them a lie told at age 3, 8, or 14 years doesn’t automatically foretell a life of dishonesty, delinquency, and crime.

Lies mean very different things at different ages. A preschooler faced with an angry, red-faced adult may lie out of fear or to fill in something or anything for what they do not understand. An elementary school–age child may lie as part of navigating a complex social situation or to fulfill an obligation to protect a best friend. Adolescents lie to provide space, time, and to cover for friends or themselves, often as a way to gain or protect their privacy.

Rarely do these lies threaten the core trust relationship between parent and children, although some moms and dads erroneously equate a lie at any age concerning any issue and of any scale as the same type of dishonesty they see in adults or even criminals.

It is important to differentiate between very different types of lies. There are pragmatic lies consistent with a child’s developmental level. These lies are similar to the lies parents told growing up and honest lies adults tell each other routinely. There are more profound lies that reflect a breach in the trust relationship with the parent. Finally, relatively few children tell lies that reflect a characterological direction of becoming a persistent liar, cheat, or a criminal.

A developmental understanding of lying can help you with the distinctions.

A 3-year-old may quickly say "No" when asked "Did you eat a cookie?" or "Did you knock the plant over?" Often, they see a very angry parent asking a question that would incriminate them. At that moment, the 3-year-old is not thinking about morality, robbing banks, or starting some insider trading. All they are is scared. They don’t understand the implication or meaning of the lie. Instead, their thinking is more pragmatic, expedient, and fearful: "If I say no, this will end. If I say yes, I don’t know what is going to happen to me."

Many parents make pronouncements that are difficult or impossible for the child to follow. To say "Don’t ever lie to me!" or "If you lie to me, I’m never going to trust you again!!" doesn’t really make sense in response to one of these pragmatic, developmental lies. I’ve had parents in my office say, "I don’t care what he or she has done, as long as they don’t lie to me." This makes all lies the same, at all ages, and puts the full force of the parental relationship on all of them.

I get concerned when parents put so much pressure on telling the truth because they believe it’s the path to moral virtue and honesty later in life. This pathway is probably much more linked to the child feeling loved and valued, as well as to the consistency on the parents’ part to living the family’s values. I often ask parents if they ever lied to their own parents when they were teenagers, and they will respond: "Of course, all the time."