I think two things that are common causes of sibling bad feelings are differences in treatment, and handling of sibling conflicts, both of which can create feelings of unfairness and resentment.

I don’t have prescriptions for those things. Kids are different and necessarily need to be treated differently. But one should be aware of how this can feel unfair to one sibling. And be aware of how your need to end conflicts and restore order can again wind up being unfair to one sibling.

I think the hardest thing is being able to see things from their points of view.