They may be yet to take their first step or say their first word, but some babies have already grasped the basics of deception before their first birthday, according to research.
The study, based on interviews with 750 parents, suggested that by 10 months about a quarter of children were practising some rudimentary form of deceit such as pretending not to hear their parents, hiding toys or eating forbidden foods out of view. By the age of three, children were more proficient, creative and frequent fabricators, according to the parents’ responses.
“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,” said Elena Hoicka, a professor of education at the University of Bristol and lead author of the research.
Until now, Hoicka said, there had been little research about the earliest forms of deceptive behaviour. “Previous research has often focused on deception as something very sophisticated requiring strong language skills and an advanced understanding of others’ minds,” said Hoicka.
The latest research drew on animal behaviour studies, which have documented apparent deception without the need for verbal communication. Chimpanzees, for instance, often hide to eat food out of sight of more dominant group members, while birds have been documented making false alarm calls in order to steal food.
“It’s not like the ability to deceive suddenly appears at three or four years out of nowhere,” said Hoicka. “The earlier forms are not necessarily all-out deception. It’s probably more about getting away with things or getting extra treats.”
“As a mother of three children myself, I can certainly vouch for how artful and wily they can be,” she added. “Hiding under the table or in the bathroom to eat sweets or chocolate is their common ploy.”
The researchers asked the parents of more than 750 children aged between 0 and 47 months from the UK, US, Australia and Canada a range of questions about their child’s deception development.
Some respondents reported their child first recognised the concept when they were as young as eight months. Deception activity was also found to be frequent. Once their child got started, the study showed that half of children reported as deceivers had done something sneaky in the last day.
From two years, deception tends to be action-based, or require only basic spoken responses, such as pretending not to hear their parent say “time to tidy up”, hiding things from others, or denial – such as eating chocolate but shaking their head to say “no” when asked if they ate chocolate.
Findings showed that by the age of three, children start to understand and engage in more types of deception, which often involves a deeper understanding of language and how other people’s minds work.
Hoicka said: “This could mean exaggerating, understatement or indeed complete fabrication such as telling a lie like ‘a ghost ate the chocolate’. They also start to withhold information, for instance accurately telling their parents their sibling hit them, while leaving out the fact that they hit their sibling first.”
She said the study should reassure parents and educators that deception was normal in toddler development and provide a guide to which types of deception might be expected, so that they could “stay one step ahead of their deceit”.
Prof Jennifer Saul, an expert in the philosophy of deception at the University of Waterloo, Canada, and co-author of the research, 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.”
The findings are published in the journal Cognitive Development.
