New research suggests that some babies begin practising deception before their first birthday, with about a quarter of 10-month-olds engaging in rudimentary deceit such as pretending not to hear parents or hiding toys. The study, based on interviews with over 750 parents from the UK, US, Australia and Canada, found that by the age of three, children become more proficient and creative liars, often fabricating stories like 'a ghost ate the chocolate'.
Lead author Professor Elena Hoicka from the University of Bristol said it was fascinating to see how deception evolves from a surprisingly young age. Previous research focused on deception requiring strong language skills, but this study drew on animal behaviour, where chimpanzees hide food and birds make false alarm calls. Hoicka noted that early deception is about getting away with things or extra treats, not necessarily all-out lying.
The study, published in the journal Cognitive Development, found that once children start deceiving, half of those reported as deceivers had done something sneaky in the last day. From age two, deception is often action-based, such as pretending not to hear 'time to tidy up' or denying eating chocolate while shaking their head. By three, children understand more complex deception involving language and others' minds, including exaggeration, understatement, and withholding information.
Professor Jennifer Saul from the University of Waterloo, a co-author, said philosophers have focused on adult deception but this study shows the complexity that begins in early childhood. Hoicka added that the findings should reassure parents that deception is normal in toddler development and help them stay ahead of their child's deceit.
