A behavioral scientist at the University of Arizona is now recommending parents have a serious talk with their kids about lying--but not to tell them that it's always wrong, rather to explain when it can be okay. "We have to get a handle on lying in social relationships early on in kids because it has implications for how they behave down the line," says Wendy Gamble. "A tendency to lie or deceive will affect the way children form and maintain relationships with others. Honesty is the basis of effective communication and healthy relationships. Rather than dismiss all lying as bad, however, we should tailor our socialization messages to reflect that deception is common and frequently socially acceptable."

Gamble bases her advice on research she and her colleagues conducted to learn why children lie. In all, they interviewed 98 schoolchildren last year in Tucson, studying both positive and negative types of lies (see chart). They presented the children with different scenarios--say, a bully looking for a child's friend--and then asked whether it would be appropriate to lie. In most cases, the children opted to tell the truth. But when they did chose to fib, it was generally for pro-social purposes--or aimed to benefit someone else, such as a friend confronting a bully. Although the tendency to lie increased with age, children as young as first grade seemed to know the difference between black and white lies. There were no gender differences.

One interesting trend in the data was that children seemed more likely to tell pro-social lies to their peers, but selfish or self-enhancing lies to their mothers. This difference also turned up in a study of college-age students. Gamble cautions that the findings are preliminary. In the future, she hopes to investigate further the roles that parents, culture and socioeconomic factors play in the patterns of lies kids tell.