However, the biggest reason for sibling rivalry is the need for exclusive parental love, approval, and attention. The intense desire each child feels to be first and best often triggers jealousy between siblings because each perceives that their parents love the other best. Imagine how threatened a child must feel when a new sibling arrives. His secure position in the family has been undermined, thus unleashing the hostility that leads to the struggle to be number one in his parents' eyes. Every family has its own issues, but they share the dilemma of how to deal with their dueling darlings.
Experts agree that some conflict is good.
Let them solve their own problems. Not only does this keep you out of the fray, but the kids benefit by experiencing verbal sparring they learn the difference between being hurtful and being clever. When it is necessary to intervene, do it calmly. Send them to separate areas for a cooling-off period. When a child has been physically hurt by a sibling, give your attention to the injured child, not the aggressor.