Live and Learn
Somewhere along the line, children realize that they can fake certain behaviors to get what they want. Your fifth-grade daughter might have a friend who knows how to smile so sweetly that most adults think she's the most enchanting child who ever walked the earth. From the behavior you've observed at your own house — particularly how this child turns her perfect behavior on in the presence of adults and off in the presence of her friends — you know that she's learned how to charm and disarm authority figures.
Because sophisticated, manipulative nonverbal communication is learned — from peers, parents, siblings, or the media — these behaviors develop earlier for some children than for others, and not at all for some kids. Your child might never adapt these kinds of gestures, even if her friends do.
You can't prevent your children from learning about manipulative body language, but if you see them using their nonverbal powers for less-than-honorable purposes (lying, cheating, taking advantage of other kids), call them out on their behavior and try to put a stop to it. While there's something to be said for an adult who knows when and where to use effective body language, a child who's well-versed in using manipulative gestures is headed down the wrong path. These kids simply can't handle the feeling of power that usually results from using dishonesty to get what they want.
Relational bullying is something that parents and teachers really struggle with, precisely because it's so hard to pinpoint. You can't make kids like and accept each other, after all, and unless a child is being threatened with physical harm, authority figures are often reluctant to step in.
