Q: My younger boy, 10, has started cutting himself when his 13-year-old brother picks on him. His older brother also is verbally abusive to him and at times to me. I’m not sure what to tell the 10-year-old. He’s a sweet boy who does great in school and has nice friends. I’ve told him he needs to express his anger in a positive manner.

Meanwhile, my husband and I have told our 13-year-old we will not tolerate this behavior. In the past, I would tell them to solve it on their own, or I would punish them both. Any suggestions?

A: It’s generally appropriate to tell children who are engaged in run-of-the-mill sibling conflict to solve it on their own. But this is not sibling conflict; this is sibling bullying.

The fact that your 13-year-old is verbally abusing both his younger brother and you is clear indication he’s gotten more than a tad too big for his britches. This is budding narcissism, and the bud needs immediate nipping.

Children your younger son’s age tend to worship older brothers, especially if their age ends in the suffix “teen.”

For a 10-year-old boy, nothing equals being accepted by an older brother. Likewise, there is nothing as devastating as being rejected by an older brother other than being rejected by one’s father. The devastation felt by your younger boy can’t be over-exaggerated, and the unfortunate fact is that for many of today’s kids, cutting has become the response of choice to feelings of worthlessness.

Telling your younger son to “express his anger in a positive manner” is well-intentioned, but that requires more emotional maturity than is possessed by your average 10-year-old. More important is what you tell his older brother.

I recommend that you and your husband inform your older son that the next time he physically intimidates, harasses or verbally abuses either his younger brother or you, he will spend all of his discretionary time for one month in his room, which you will strip of any and all entertainment.

During his confinement, his lights will go out at 8 p.m., seven nights a week. If, upon his release, any such incident occurs again, his confinement will be increased to two months, and you will either throw or give away everything he owns that is not absolutely essential.

Your older son’s behavior is serious stuff, but it is the beginning of even more serious stuff.

It requires an equally serious response from you and your husband.

A psychologist, Rosemond answers parents’ questions on his website, www.rosemond.com.