I thought this article was particularly interesting, especially now that I have my own experiences to compare with the thought therein.

An excerpt:

Many parenting Websites and books advise parents to just let lies go—they’ll grow out of it. The truth, according to Talwar, is that kids grow into it. In studies where children are observed in their natural environment, a 4-year-old will lie once every two hours, while a 6-year-old will lie about once every hour and a half. Few kids are exceptions.