When do children start lying?
Children can learn to tell lies from an early age, usually by around three years of age. This is when your child starts to realise that you aren’t a mind reader, so he can say things that aren’t true without you always knowing.
Children lie more at 4-6 years. Your child might get better at telling lies by matching her facial expressions and the tone of her voice to what she’s saying. If you ask her to explain what she’s saying, she’ll usually own up.
When children reach school-age, they might lie more often and can be better at lying. The lies also get more complicated, because your child has more words and is better at understanding how other people think.
By eight years, children can lie successfully without getting caught out.