Children and youth

Study: Babies Start Deceiving as Early as 8 Months

Is childhood deception a sign of healthy development or a troubling behavior that parents should worry about?

Published MAR 17

Study: Babies Start Deceiving as Early as 8 Months

Story

Above: German toddlers in the "Frogs" group engaged in play with building blocks at Spreekita Kindergarten in Berlin on May 3, 2007. Image credit: John MacDougall/AFP/Getty Images

The Facts

A University of Bristol-led study found that about 25% of children begin to understand deception by 10 months old, rising to 50% by 17 months, with researchers identifying 16 distinct types of deceptive behavior in children under 47 months.
University of Bristol
Daily Mail
The study, published in the journal Cognitive Development, was based on responses from parents of more than 750 children aged up 47 months old from the U.K., U.S., Australia and Canada. The earliest reported instance of deception was observed in an eight-month-old.
Sciencedirect
Independent
PhillyVoice
Lead researcher Elena Hoicka, a professor of education at the University of Bristol, said, "It was fascinating to uncover how children's understanding and usage of deception evolves from a surprisingly young age and builds in their first years so they become quite adept and cunning 'little liars.'"
Huffington Post
The Sun
From age two, the study claimed deception in children tends to be action-based, such as pretending not to hear instructions or hiding objects. By age three, children engage in more complex tactics, including exaggeration, withholding information and deliberate distraction.
University of Bristol
The Times of India
Co-author Jennifer Saul, a professor of philosophy at the University of Waterloo in Canada, said: "Philosophers have long reflected on the morality of human deception, but always focused on adults deceiving one another. This study shows just how much complexity gets overlooked by that focus."
Independent
PhillyVoice
Hoicka said parents can be reassured that deception is "entirely normal in toddler development" and that the findings can help parents understand which types of deception to expect at each age. The study's findings are also noted as relevant for educators.
Huffington Post
The Sun

Sources Split

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CENTER

RIGHT

ESTAB
CRIT

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PRO
ESTAB

The Spin

Narrative A

Babies are sneakier than anyone thought — research shows kids as young as 8 months old are already pulling deceptive moves, and by 17 months, half of all children are in on the game. This isn't some rare behavioral quirk; once kids start deceiving, over half do something sneaky within a single day. Deception is a normal, even healthy, part of child development that signals growing social awareness and brain development.

PhillyVoice

University of Bristol

Huffington Post

Narrative B

Early deception in babies isn't a moral failing — it's pure instinct driven by outcomes, not ethics, and parents who panic are missing the point entirely. Kids aren't calculating liars; they're sharp observers learning from their environment, including the small social fibs adults model every day. The real takeaway is that calm, consistent guidance during this phase builds a foundation for genuine honesty rather than just rule-following.