I highly recommend the book Predictably Irrational by Dan Ariely. In this book, Dan explains how we think we are able to make rational practical everyday decisions, but we are driven to make irrational decisions by both internal and external forces of which we may not be very aware. One chapter about dishonesty has me thinking about my work with teenagers. This chapter concludes that the further one is from committing a direct offense against someone, the easier it is to be dishonest. It also concludes that everybody lies and cheats a little bit when 1. given the opportunity2. when there are low likelihood of consequences and 3. when it's about something small.

Many of my parents complain about their inability to trust their teenager. Whether it's sneaking out, having sex, doing drugs, being home on time, many teens are dishonest to their parents about their actions. In general, teenage dishonesty comes more in the form of "lying by omission" (leaving stuff out), rather than "lying by commission"(telling a bald-faced lie). In my experience it is harder for a teen to be able to to tell a complete lie to a question like, "Have you ever smoked marijuana?" But they will definitely fudge on a question like, "How often do you smoke marijuana?" (My usual rule of thumb is to double the answer to that question) . When the answer comes back "once a month", I usually think "twice" is probably closer to the truth. So my main points are 1. don't trust your teenagers and 2. don't think they are the devil's spawn when they lie to you. Lying is natural and normal. If you catch your teen in a lie, don't put them in the "I know the truth and you need to tell me now or you are in big trouble" corner. They will continue to lie. Tell your kids what you know, point out the facts and be direct. They will tell you an answer that approximates the truth, leave a couple things out and probably minimize their misbehavior, compare themselves to everyone else, and make up a ton of excuses, but then you can move on to a consequence and but the issue behind you. If the stories don't add up, just agree to disagree on the exact facts of the matter. Too many parents get hung up on the complete truth being told, and I think you have to approach these situations with the reality that the complete truth will probably never really come out. In my experience, the process of nagging the truth out of your kids leads to more distance, less openness, sneakier behavior and more secrets being kept.