It is difficult when you have several kids to avoid « clashes » between them. I have 3 with the two largest are (fake) twins and sometimes it really in every sense. Then how to manage these crises as parents?
When they fail to agree, the parent must intervene but not any how. Here are some simple tips that can help you.
First, do not take sides, need to remain impartial and not screaming (or just to hear). Ask them calmly why, they compete as the dressers. And especially each expresses itself, for not exiting in a downward spiral. It is necessary to bring them to analyze their dilemma to find all solutions to their problem without influence them.
Then, it is necessary that they reflect together on the best solution for them, so everyone is happy and that everyone finds his account. But then again, it is they who must choose and not you, the parent.
Finally, if the solution they have chosen is good, explain that dialogue is important and that we do not achieve anything in is unnerving.
We parents must set a good example to our children and put them on the right path, so that later, do them same as between siblings but also between boyfriends/girlfriends. In this case, punishment, is not at all the right solution, this will not solve the problem, on the contrary.