Q. Our two girls, ages 3 and 5, seem to argue over everything. How can we get them to stop?

A. Listening to your children fight is a form of parental torture, similar to enduring whining but even more distressing. When our two girls still had a harmonious relationship, until ages 3 and 6, we were warned by parents of older children that the peace wouldn't last. They were right. Garden-variety arguing, a certain amount of which is normal, starts when the younger child becomes capable of threatening the older one's supremacy, or at least capable of knowing just when to topple the block tower her sister's so carefully built.

Psychological wisdom has it that sibling rivalry and chronic fighting may also stem from parents' comparing one child with another, however unwittingly. "So tell your children what each one is good at, but one on one, when you're alone with a child at bedtime, for instance," says Peter Goldenthal, Ph.D., author of Beyond Sibling Rivalry.

Emphasize that each person in the family has strengths and weaknesses and is loved as an individual. If everyone feels valued independently, it's easier for them to develop a sense of mutual belonging and family pride -- the feeling that my sister's success is my success, her sorrow my sorrow.

Some basic house rules can help too: Toys must be shared or they'll be banished to shelf Siberia. Hitting or shoving buys you time in the penalty box. Lately, I've been using a couple of other tactics as well. I ask my daughters how they'd feel if their father and I had six fights a day and they had to listen to it. That snaps them out of a jag for a little while. But mostly, I remind them (with frequent success) that they're stuck with each other -- that long after Mom and Dad are gone, a sister will be there, so they might as well make the best of the relationship.

Trisha Thompson is a contributing editor to PARENTING magazine and a former editor-in-chief of BabyTalk.

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