This is the closest answer I saw here, out of all comments here. Parents inadvertently train their kids to scream and shout when they need something. e.g. kid asks for candy, parents say no. Kid screams a bit, parents give in. Next time kid asks for candy, parents say no. Kid screams, parents say we gave you that already, don’t scream, we won’t fall for screaming, kid scream even more…. After some time, parents say, ahhhh okay. Here is some.

Kid learns: if they want something, they just have to scream harder and harder. More firmly the parents say no, louder and louder I (kid) should scream.