<B>Q: My 21-month-old has started hitting. Whenever he hits his 4-year-old sister, I put him in his crib until he calms down. Recently, however, his sister has started hitting back. I don't want her thinking that I go easier on him when it comes to discipline. How do I implement fair and effective punishment for the same offense for children of different ages?</B>

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A:</B> I sense that you're over-thinking this situation. No matter how you discipline the two children when they get physical with one another, your daughter is going to feel that her punishment is unfair. In fact, no matter the offense, if the child in question doesn't think the punishment is unfair, then it's probably ineffective. "That's not fair!" should be music to a parent's ears. Even though your son "starts it," you should punish both of them. If you don't, your daughter is likely to begin provoking her brother to hit her.