A. It's most likely just normal toddler behavior. Pick up any child-development book and you'll find that there are several peak times of interest in masturbation -- the second year of life is one of them. Thus an 18-month-old who sticks a doll between her legs and starts gyrating.
Just as it's natural for your daughter to explore her body parts and see what feels good, it's also natural for you to be surprised and even uncomfortable when you see it. Many parents feel strange witnessing children's displays of sexuality. But the more attention you pay, the more the activity becomes infused with the allure of the forbidden or, worse, the message that touching herself is dirty.
You may have also seen media reports that suggest such activity may be a sign of abuse. But "children who have been abused don't have just one symptom," says Steven Kairys, M.D., the immediate past chair of the American Academy of Pediatrics's committee on Guidelines for the Evaluation of Sexual Abuse of Children. "You'd see several signs, such as withdrawal, sexual behavior with other kids, and disturbances in sleeping and eating." If that's the case, ask your pediatrician for advice. Otherwise, keep your reactions low-key -- she's only doing what comes naturally.
Trisha Thompson is a contributing editor to PARENTING and a former editor-in-chief of BabyTalk.