Tweens: growing fast and stretching the truth
When we had a Halloween party for my older daughter, Aurora's, third-grade class, my husband made up a ghost story about "the rundown house up the block." At the end, the girls cried, "Can we go see it?" At 9, they'd developed concrete ideas of truth and falsehood but were still naive about the gray area in between.

And speaking of gray areas, tweens are also apt to gloss over details of their lives they once freely spilled about. Don't be surprised if your child keeps mum about things she would have shared with you a year or two before, like the latest lunch-table gossip. This new secretiveness isn't dishonesty or a sign that your child is up to anything wrong. In fact, it reflects her growing maturity. "Kids who tell everything to their parents at age thirteen or fourteen are not growing up," says Dr. Brody.

Of course, as your child gains more independence, he may take advantage of it by pulling a fast one from time to time. When 9-year-old Joey DeMille of San Diego asked his mother to stop "nagging" him about completing his daily reading log, she agreed to back off and let him take responsibility. "For the entire month of January, I didn't ask him to show me his log," she says, and Joey swore that he was filling it in daily. But when the time came to turn in the log, his mother was shocked to discover that it was nearly blank. "He had been lying to me all month long!" she says.

An occasional lie about homework, chores, or toothbrushing, while aggravating, is not unusual at this age. The best response usually is to simply express your displeasure. But if a tween lies chronically, he might need professional assistance to sort things out. "Children who are anxious, who feel that they can't handle some kind of situation, may lie," says Dr. Berger. "It could be a sign of any number of stresses that the child is under." It could also be the sign of a smart kid who finds lying a convenient tactic.

The best way to steer your tween toward greater honesty? Set a good example yourself (no fudging his younger brother's age to get cheaper movie tickets) and talk to him about how lying can damage your credibility and relationships. "It's the kind of lesson that doesn't sink in immediately," says Crossman. What lesson ever does, especially with kids that age? But chances are your child will grow out of his fibbing -- and into an honest-to-goodness adult.

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