Take It Behind Closed Doors
Understanding that this type of behavior is normal doesn't mean that you should allow your child to launch an exploratory mission in his pants in the middle of the frozen foods section. "Parents should tell their children that everyone has private body parts, and that those parts should not be shown or touched in public," says Dr. Arinoldo. "Explain the difference between public behavior and private behavior."
By the time your child is potty trained, he or she has come to understand that certain activities happen in certain places; we sleep in our beds, eat at the kitchen table, and pee in the bathroom. While it sometimes takes very young children a few years to really grasp the concept of public versus private, consistent reinforcement and patience on the part of parents can make the idea stick. By age six, most kids understand the difference.
In the meantime, if you see your child beginning to touch or rub while you're at home or out in public, gently and quietly remind her that this is something she should do when she's alone. If she wants to "play that game" she should go to her room to play privately. Once that boundary is established, stick to it. If you see your child masturbating in his or her own room or in the bathroom, ignore it. And don't feel that you have to rush to have an uncomfortable "birds and bees" conversation with a preschool-aged child.
"Children at this age are limited in their cognitive understanding of the world," Dr. Arinoldo says. "Don't attempt to discuss sexuality with the child; it will only confuse them. Instead, take a non-judgmental attitude toward your child's inquisitiveness and answer questions in an age-appropriate way."