A study based on interviews with 750 parents has revealed that some babies grasp the basics of deception before their first birthday. By the age of 10 months, about a quarter of infants were practising rudimentary deceit, such as pretending not to hear their parents, hiding toys, or eating forbidden foods out of view.
The research, led by Professor Elena Hoicka of the University of Bristol, found that by three years old, children became more proficient and frequent fabricators. Examples included hiding under tables or in bathrooms to eat sweets, and telling lies such as 'a ghost ate the chocolate'.
Professor Hoicka said previous research had often focused on deception as something requiring strong language skills and advanced understanding of others' minds. The latest study drew on animal behaviour research, noting that chimpanzees and birds also exhibit deception without verbal communication.
The findings, published in the journal Cognitive Development, show that once children started deceiving, half of those reported as deceivers had done something sneaky in the previous day. From two years, deception tends to be action-based or require only basic spoken responses, such as denying eating chocolate while shaking their head.
By age three, children begin to engage in more complex deception involving a deeper understanding of language and others' minds, including exaggeration, understatement, and withholding information. Professor Hoicka said the study should reassure parents that deception is normal in toddler development.
