“Frustrated” writes: My husband and I watch our grandchildren a couple Saturdays each month. We disagree on how to handle the situation when my grandson, age 5, hits out at his sister, age 3. It is usually because she has picked up a toy, often one he’s not even playing with. I think it is not unusual behavior and needs to be handled gently, and my husband thinks the 5 year-old should be punished in some way.

Dear Frustrated: Jealousy at that age is “normal.” I say to worried mothers, “How would you feel if your husband brought home another wife a couple years after you two were married?” While each child holds a special place in their family (i.e., the boy is a boy and is the first-born; the girl is a girl and is the “baby.”), they don’t have the perspective to see that. And the older child probably doesn’t have a good feeling about his reaction, either. Shaming him won’t help him to feel more generous.

• I would stay close by physically when they are playing, which helps when safety is endangered and intervention is called for– and to help children feel reassured by an adult’s presence.
• When my children were young, I had a stash of toys that were mine. When young friends came over, those were the toys that came out, and no one had to “share.”
• I would also establish a rule that whoever is playing with a toy gets to play with it until he or she is done, then make it clear that when the child has decided their turn is over, it is over—no going back. (When that toy belongs to the child, maybe it can be put away when he or she is finished with it.)
• For minor squabbles, it is best to stay out of the way. Even a 3 year-old can defend herself against a 5 year-old brother when allowed to. And other feelings of liking to play together can surface once the dispute has been gotten over. (And it is also best not to take sides, but intervene with both if necessary, letting them say how they feel and/or giving them the words to use to express themselves.)
• Are the children in need of some new distraction, stimulation, or physical exercise? They are so active at those ages. Maybe your husband (or yourself, of course) can take the older child out for a walk or to a nearby playground, for example.
• In the long run, a child’s positive sense of self is the best prevention to the kind of jealousies that siblings inevitably can crop up, even later, with friends, and even as adults, with partners, co-workers. I found that enjoying time with each child one-on-one on a regular basis strengthens the relationship and builds those positive feelings in a child that they are worthy and special in their own right.
• And, are we good role models in how we handle conflict? Talking about negative feelings in constructive ways is a good thing.

(I recommend also: http://www.kidshealth.org/parent/emotions/feelings/sibling_rivalry.html)