M.,
When I was younger and worked in a store, I seen alot of kids
scream for things they didn't need, I even seen with relatives who had kids that screamed, for everything and anything. I determined then, in my mind, I would never let my kids do that,
so I made a rule, I started using it when I babysat for different relatives and families.
My rule is this:
If you have to cry or scream for anything at home or when we are out shopping or anywhere else, You Automatically DON'T GET IT! End of, so don't try to ask again.
That was my rule and I enforced it. If you use it and you don't follow through with it, they will not take you serious when you use it again. You must enforce it.
I have never had a problem with kids screaming. Because I enforced that rule, when kids played together around me, they
never faught over things because they knew I would just go and take it away and nobody could have it, either they shared it or I took it. Majority of the time they shared it and only kids who did not know the rule threw the fits over toys.
Good luck.
Oh, for the kids that scream for no reason at all,
tape record them, at the end of the day let them listen to it without telling them who it is, then ask them how they would punish the child doing this, then after they set the punishment, either tell them who was screaming on the tape. And follow through with the punishment they set, within reason. Some kids will want to really make the punishment bad. OR. Once they know it's them, discuss a punishment that will work and help them to control themselves at the same time.
Teaching kids to control themselves (attitudes) at an early age is good. Remember, uncontrolled tempers and fits of rage can get out of control in their teenage years, where it would have of been avoided, had you taken the time to deal with them when they were younger.
Hope this helps.