As a baby becomes a toddler, she and her older sibling will discover many new ways of playing together, like peekaboo and hiding.

A 4-year-old and his 18-month-old sister imitate each other as they march around. This is a reward for their battles. They have a hilarious time throwing food off the table. The older one learns to skip. The toddler tries but gets her feet tangled. They both laugh until they’re breathless and red in the face.

Along with the new rewards of a real playmate, the toddler also brings the older sibling a new threat. Not only can she now move into his space, she can also begin to compete on his turf. She can’t live up to him, of course; but now she can try. And he knows it.

“She took my Lego and hid it.”

Every game they play together seems to end in a fight. How much should parents be involved? The toddler wants to be rescued, and the older child wants to be reassured that you recognize his superior prowess.

If you have been nearby enough to watch the buildup, you may know how each one has contributed to it. She seduces him with her almost unobservable biddings. He is all ready to respond. He takes over and bosses her around. She reacts with a half-joyous, half-protective squeal: an enticing but confusing message that he can’t resist. That sets the tone.

He starts tickling her and won’t stop even when he’s pushed her over the edge. Her laughs become screams for a parent. If the parent tries to figure out who is to blame (which is hopeless) or steps in and resolves the situation rather than letting the children learn to settle their own conflicts, their struggles will intensify.

Though they may not have planned it, the children will discover what a thrill it is to draw a parent into their squabbles. The triangle is more exciting than a twosome.

As the toddler learns how to be a “victim” and the older child tries out the rewards of teasing the younger one, the presence of a parent adds drama to their play. It is very hard for a parent to stay out of it.

When my younger brother and I were little, we knew exactly how to get our mother off the phone, how to call her in from outside or from another room. I can remember the plotting look we would share with each other. Then, we’d go to work. My calling my mother didn’t always bring her, but a few screeches from my brother worked every time.

Older children (6 or 7) aren’t as likely to have prolonged squabbles with a toddler sibling.

Instead of wanting to compete, they may recognize their superiority and their ability to nurture. But they may tease as they brush by, or even set up a complex trap for the younger child. Then they’ll chortle as the trap gets its victim. They can be merciless as they test their prowess and the younger child’s resourcefulness.

Siblings who are close in age (two years apart or less) are more likely to spend long hours in fights with each other. Their persistence, inventiveness and tolerance for repetitious sparring reflect their need to test each other, and to learn how to handle themselves.

In the early years, fighting is also the result of the children’s limited abilities to share, take turns, tolerate frustration, put off gratification, negotiate and compromise.

With patience and repetition, parents can help them learn these new skills without trying to determine who started the squabble or which child is at fault.

DEFUSING SQUABBLES

Be sure the younger one is safe. Remove dangerous toys, and separate the children if hitting gets out of control.

Divert the older child with an interesting project or peers to play with.

Help the older child with his anger by talking with him and helping him understand it, by reading stories about angry situations, or by playing out angry feelings with puppets or action figures.

After stopping a fight that has gotten out of control, hug each child and give them reassurance: “You can handle it with each other. I’m here to help when you need me. But it’s your job to learn to get along with each other.”

This article is adapted from “Mastering Sibling Rivalry: The Brazelton Way,” by T. Berry Brazelton, M.D., and Joshua D. Sparrow, M.D., published by Da Capo Press, a member of The Perseus Books Group.

Questions or comments should be addressed to Dr. T. Berry Brazelton and Dr. Joshua Sparrow, care of The New York Times Syndicate, 620 Eighth Ave., 5th Floor, New York, N.Y. 10018. Questions may also be sent by email to:

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