Most childhood lying does not lead to serious problems in adulthood, and only certain kinds of lying behaviour is associated with later psychological or legal issues, a new study has found.
“Children do not all follow the same developmental pattern of lying,” said Victoria Talwar , a professor in the Department of Educational and Counselling Psychology and lead author of the study. “Most children in our study showed low or declining levels of lying over time. For most, lying is not a problem behaviour.”
However, children who lied frequently or whose lying increased over time were also more likely to show early aggression and impulsivity, and to later show anti-social personality symptoms and have criminal convictions in early adulthood, she explained.
The study, conducted by researchers from McGill University, Université de Montréal and John Jay College of Criminal Justice in New York City, used data from the Quebec Longitudinal Study of Kindergarten Children. Its members attended French-language kindergarten between 1986 and 1988. At the time, 2,000 of them were randomly selected as a representative sample and an additional 1,017 were selected as they showed behavioural problems.
The study is among the first of its kind on this topic.
The researchers looked at study data about participants’ lying from ages 6 to 19, as reported by their parents and teachers, and identified groups of participants with similar patterns of lying over time (e.g. occasionally, frequently, increasingly, etc.).
They then checked whether these “lying trajectories” were associated with other traits in childhood, such as aggression or impulsivity, or later outcomes, such as mental health diagnoses or criminal records, using data on psychiatric symptoms at age 22 and juvenile and adult criminal records up to age 25.
“This study helps us start to understand and distinguish between normal development and patterns that may benefit from early help,” Talwar said. “It also helps us reduce stigma about lying while also improving prevention for long-term negative outcomes.
“Persistent and increasing lying across time – especially when in combo with aggression and impulsivity – could signal the need for early support and intervention; rather than just reactive punishment,” she added.
Talwar, who has long researched the topic of children and lying, said she hopes future studies can track individuals further into adulthood to examine long-term social, occupational and relational outcomes, as well as help clinicians better support individuals’ moral and social development across the lifespan.
“ The Long View: Lie-Telling Trajectories, Ages 6 to 19 years ,” by Victoria Talwar (McGill University), Angela M. Crossman (John Jay College of Criminal Justice), Kristy Robinson (McGill University), Marie-Claude Geoffroy (McGill University), Sylvana Côté (Université de Montréal), Richard E. Tremblay (Université de Montréal), and Frank Vitaro (Université de Montréal), was published in Development and Psychopathology .
Development and Psychopathology
Data/statistical analysis
People
The long view: Lie-telling trajectories, ages 6 to 19 years
27-May-2026