There’s a great piece in New York Magazine about why children lie. In short, they do so because their parent do. The good news if you’re a parent, is that if your child is telling porkies from a young age it is a sign they are quite smart—the brightest start lying around age 2. The speed at which children lie is quite astonishing: researchers found that the average 4 year old lies every two hours and 6 year old every 90 minutes. One other interesting statistic is that teenage rebellion peaks at between14 and 15.