(Susie Ghahremani for The Washington Post)

My son is extremely competitive with his sister, although she doesn’t provoke him or even act like she wants to compete with him. She pesters him in other ways and then they end up in an argument no matter what we do.

We’ve tried to be the peaceful referees. We’ve tried to negotiate with them and to make them negotiate with each other. We’ve taken away their privileges. You name it and we’ve tried it, but we still can’t create any peace in our house. This is what I desperately need because I work full-time and it’s exhausting to deal with this chaos day after day.

A. Let’s talk about the minor problems first.

You don’t have to worry about your son’s drifting ways because, like many young teenage boys, he’s too busy gulping down all the newness in his life to be passionate about anything else. You don’t have to worry about your 10-year-old daughter, either; she’s bound to brush her hair and wear nice clothes to school by the time she’s 12.

You should be concerned that she wants every activity to suit her interests and her timetable, however — a sign that she has probably gotten away with this behavior a few too many times. The less you try to please her, the sooner she will learn to compromise.

Sibling rivalry is a much bigger problem. If children don’t learn to be civil with each other while they are growing up, they may stop trusting each other. This may make it hard for them to get along with their roommates at college; to work well with their colleagues at the office; and to have a happy and enduring relationship with their spouses, especially when life gets stressful or boring or money gets tight. And if you still don’t think that childhood squabbles can affect your children later, read “The Little Way of Ruthie Leming” by Rod Dreher, a beautifully written memoir about the author, his sister and how their rivalry sowed the seeds of mistrust, even in their garden of love.

Fortunately, the rivalry between your children can be corrected once you realize that your children are carrying on simply because they want as much of your attention as they can get. If they get more attention for bad behavior than they get for good behavior, guess how they’re going to behave?

It may be tempting to negotiate with your children, to referee their arguments and to placate your daughter’s whims and wishes, but these corrections aren’t working — and the only good discipline is the kind that works.

It’s time to tell your children that you won’t put up with their arguments anymore and that this is nonnegotiable. And then give them a new rule, but give it when they are fairly peaceable. Give it only once, so your message doesn’t turn into a nag. They need to know that you and their dad will go to your room the next time they start squabbling and that you’ll stay there until they can be civil with each other. If that means that you can’t go into the kitchen to cook their dinner, so be it. They’ll just have to go to bed without it. This may sound harsh, but children have to learn that everything they do — or don’t do — has a consequence.

They won’t believe that you’ll actually carry out this rule unless you disappear the next time they start to quarrel and refuse to respond to them no matter how loudly they yell. Since no one wants to clap with one hand, you can expect your children to look for more positive ways to get your attention, but only if you give them much more attention when they’re behaving themselves than they get when they’re bickering.

Everything you do — or don’t do — has a consequence, too.

Send questions about parenting to advice@margueritekelly.com.

Read a transcript of a recent live Q&A hosted by Kelly at washingtonpost.com/parenting , where you can also find past Family Almanac columns. Her next chat is scheduled for June 27.

Q. My husband and I have a 10-year-old girl and a 14-year-old boy who are unique, terrific and very smart, but their idiosyncrasies are driving me wild.

The older child sort of drifts along and has no real passion for anything, while the younger one is extremely stubborn and will only cooperate when the activities and projects suit her interests and are on her timetable. She also lashes out at anyone who tries to brush her hair more than once a month or asks her to go to school wearing pants without any holes in the knees.

The arguments between my children bother me the most, however. Although they fight a little less these days, they can’t be in each other’s company for more than five minutes before they start to bicker. The warfare is nearly constant.