• Posted June 1, 2026

Childhood Lying Is Normal and Rarely Signals Behavioral Concerns, Study Says

The dog didn’t eat your homework. You started it, not your sister. Your phone did not die when I was trying to reach you. 

Kids’ lies can infuriate adults, no doubt.

But most lying children will not grow up with criminal records or certain mental health diagnoses, a new study says.

Occasional lying is common among kids and no cause for alarm, researchers reported May 27 in the journal Development and Psychopathology.

Only children who lie frequently or whose lying increases over time are more likely to show early aggression and impulsive behavior, researchers wrote. Such kids have a higher risk of antisocial personality and criminal convictions as young adults.

“Children do not all follow the same developmental pattern of lying,” said lead researcher Victoria Talwar, a professor of educational and counseling psychology at McGill University in Montreal.

“Most children in our study showed low or declining levels of lying over time,” she said in a news release. “For most, lying is not a problem behavior.”

For the new study, her team tracked more than 3,000 French-speaking children who were part of a long-term research project. They attended kindergarten in Quebec between 1986 and 1988.

As part of the project, parents and teachers reported data on the children’s lying and other behaviors from ages 6 to 19.

Researchers used that data to sort kids into groups with similar patterns of lying over time – occasionally, frequently, increasing or decreasing.

The team then compared these “lying trajectories” to negative childhood traits like aggression. The children were followed up to age 25 to see if they had mental health diagnoses or criminal records as young adults.

“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.

More information

The University of Utah has more on why young children lie.

SOURCES: McGill University, news release, May 27, 2026; Development and Psychopathology, May 27, 2026