Persistent Lying In Childhood May Predict Serious Problems Later In Life

Most Kids Grow Out of Lying. For Some, the Pattern Runs Much Deeper

Most children fib. Most grow out of it. But a new long-term study finds that for a meaningful slice of kids, lying can signal serious trouble ahead in adulthood, including violent crime and a diagnosis tied to a lifelong disregard for other people.

Published in Development and Psychopathology, the study followed 3,017 children in Quebec from around age 6 to age 19, making it one of the first long-term studies to follow reported childhood lying all the way into early adulthood. Researchers gathered reports from parents and teachers at multiple points over the years, then checked what became of those same children once they reached their twenties.

Importantly, the study cannot prove that lying caused later crime or antisocial traits. It found only that certain detected patterns of lying traveled alongside other risk factors, and all findings should be treated as exploratory rather than as firm conclusions.

Most Kids Lie, But Not All Lie the Same Way

Researchers sorted children into distinct groups based on how their lying behavior shifted over time. Teacher reports pointed to three patterns. About 73% of children showed consistently low and slightly declining detected lying from ages 7 to 15. Another 22% started out lying at a higher rate and kept increasing through adolescence. A third group, about 5%, started as the most frequent liars but dropped sharply, reaching near-zero reported lying by age 15.

Parent reports told a similar but not identical story. The biggest group, 58% of children, showed moderate and stable lying across time, a pattern parents consistently detected over many years rather than isolated incidents. Another 30% showed low and declining lying. The remaining 12% showed lying that climbed during middle childhood and then fell back before adolescence ended.

One consistent finding across both parents and teachers: most children were not frequent liars, and lying tended to hold steady or decrease over time rather than spike in adolescence. That actually surprised the researchers, who had expected a clear teenage peak based on earlier studies.

When Childhood Lying Becomes a Red Flag

Perhaps the most telling part of the study, though, was what came later in life. Children in the higher-lying groups were significantly more likely to have criminal records in early adulthood and to meet criteria for antisocial personality disorder, a condition marked by persistent manipulation, disregard for rules, and lack of remorse, at age 22.

For teacher-reported lying, the group showing increasing dishonesty had more violent and non-violent crimes on their records than the low-lying group, along with much higher levels of aggression at age 19. Among parent-reported data, the group with stable, long-term detected lying had more criminal convictions and antisocial personality disorder criteria than either of the other two groups.

Two early factors predicted which group a child ended up in. Children rated as more aggressive by parents at age 6 were more likely to land in a higher-lying group. Children rated as more impulsive by teachers at age 12 were also more likely to belong to a persistently or increasingly lying group. Aggression and impulsivity early in life, in other words, appeared to point toward the more problematic lying paths years down the road.

Parents and Teachers Often See Different Children

Parents consistently reported higher levels of lying than teachers did. Researchers attributed this to parents spending more time with their children, knowing their habits more intimately, and having a lower threshold for noticing when something doesn’t add up. Teachers, by contrast, observe children in more structured environments that may offer fewer opportunities for that kind of deception to surface.

Parent and teacher reports also didn’t align closely with each other at any particular age. Rather than treating that as a flaw, the researchers argued it reflects the reality that lying varies meaningfully by context. Home and school are very different social environments, and dishonesty doesn’t necessarily look the same across both. Gender differences appeared only in parent reports, with boys more likely than girls to fall into groups showing higher or more stable lying.

What This Means for Parents and Schools

Most children lie at low rates, and that behavior tends to decline naturally as they get older. But when lying is frequent, persistent, and accompanied by early aggression or impulsivity, it may be worth paying closer attention. According to the authors, identifying these patterns early could help guide targeted support before the behavior becomes entrenched.

For a long time, lying in children has largely been treated as a moral failing to be corrected with discipline and little else. For some children, though, persistent dishonesty may be less about bad character and more about a developmental trajectory that, caught early enough, might be steered in a better direction.

---

Disclaimer: Results from this study are exploratory and observational. They reflect associations found in a specific population and should not be used to make judgments about any individual child. Parents or caregivers with concerns about a child’s behavior are encouraged to consult a qualified mental health professional.

---