Whether we're 2 years old or 62, our reasons for lying are mostly the same: to get out of trouble, for personal gain and to make ourselves look better in the eyes of others. But a growing body of research is raising questions about how a child's lie is different from an adult's lie, and how the way we _ changes as we grow. "Parents and teachers who catch their children lying should not be alarmed. Their children are not going to turn out to be abnormal liars," says Dr. Lee, a professor at the University of Toronto and director of the Institute of Child Study. He has spent the last 15 years studying how lying changes as kids get older, why some people lie more than others as well as which factors can reduce lying. The fact that children tell lies is a sign that they have reached a new developmental stage. Dr. Lee conducted a series of studies in which they bring children into a lab with hidden cameras. Children and young adults aged 2 to 17 are likely to lie while being told not to look at a toy, which is put behind the child's back. Whether or not the child takes a secret look is caught on tape. For young kids, the desire to cheat is big and 90% take a secret look in these experiments. When the test-giver returns to the room, the child is asked if he or she looked secretly. At age 2, about a quarter of children will lie and say they didn't. By 3, half of kids will lie, and by 4, that figure is 90%, studies show. Researchers have found that it's kids with better understanding abilities who lie more. That's because to lie you also have to keep the truth in mind, which includes many brain processes, such as combining several sources of information and faking that information. The ability to lie -- and lie successfully  -- is thought to be related to development of brain regions that allow so called "executive functioning", or higher order thinking and reasoning abilities. Kids who perform better on tests that involve executive functioning also lie more. What's the purpose of children telling lies?
To help their friends out. To get rid of trouble. To get attention from others. To create a popular image.