My children (7&9) always seem to be trying to get each other into trouble. The frequent sniping, digs, put-downs, and exclusion cause me concern. Many times the fighting comes down to a control issue: who is allowed in whose bedroom, authority over toys ("that's mine and I didn't say you can play with it"). Sometimes the argument starts to get physical, at which time I intervene.
I want them to be friends. Do I let them sort things out for themselves? How can I get the competitiveness and fighting to stop? How do I foster their friendship rather than rivalry?
I am looking for advice on how to proactively avoid sibling rivalry because not everyone grows out of it.