Q. My 5-year-old attends a voluntary pre-kindergarten program. Her teacher has called and sent home notes because my daughter and two other girls (who all got along at the beginning of year) are being mean to each other.

They will pair up each day and leave the third one out, resulting in crying and hurt feelings. The teacher also says my child sometimes will not let others play with her or sit beside her. I have tried talking to her about being nice to classmates and how her behavior hurts others but to no avail. When a negative note comes home, she is sent to her room for time-out but this does not faze her. I don't understand why she behaves this way. Any suggestions?

A. I could have told you that time-out would not faze your daughter. Time-out works fairly well, albeit not reliably, with toddlers as well as with already well-behaved children who only require the occasional low-level wake-up call. It does not work well, if at all, in the face of either chronic misbehavior or BIG misbehaviors, and the problem you're describing is BIG. It is cruel, and your daughter is rapidly becoming addicted to the "rush" of superiority that it gives her. If only for her sake, this needs to be stopped, and stopping it will require that you get her attention and create a permanent memory.

But before I go there, I should also mention that you are committing yet two other disciplinary errors that are common to modern parenting. First, you are trying to talk your daughter into behaving properly. I call this "yada-yada discipline." As you've discovered, talking yourself blue-in-the-face will result in nothing but an increasingly blue face. It is an exercise in futility.

Second, you are trying to understand the "why" of your daughter's behavior. I call this "psychological thinking," and it is not only futile, but also counterproductive. Every psychological theory you generate concerning her behavior causes you to (a) question whether she is truly responsible for what she's doing and (b) delay action, and ACTION is what's required here.

I've already given you the psychology of this problem, but I'll repeat it in other terms: Children have an exceptional propensity for cruelty. Causing emotional or physical pain (the former being more typical of girls, the latter of boys) produces feelings of dominance, advantage, and superiority, which is to say that bullying in any form is addictive. Needless to say, the earlier the addiction is nipped in the bud, the better for both the child and his or her future potential victims.

With that in mind, here is the particular form of nipping that I recommend: Since this is a voluntary pre-kindergarten, tell the teacher that you intend to hold your daughter COMPLETELY responsible for the problem. Make sure you do this with your daughter standing by your side. Ask the teacher to please call you immediately when the problem occurs, at which time you will drop whatever you are doing, come to the school, retrieve your daughter, and take her home where she will be confined to her room for the remainder of the day, with early bedtime. To deepen the impression this makes, strip her room of her favorite things for the duration of her "therapy."

Stop talking! Stop trying to understand! Act! Be intolerant! Nip without prejudice! Someday, your daughter will thank you for it.

Family psychologist John Rosemond answers parents' questions on his Website, www.rosemond.com.