Theoretically :
Have you tried to embrace a child with hysteria? It helps to calm and does not cause pain to the child, unlike the spleen and other inadequate methods.
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Either you haven’t seen children, or you have a real hysteria.
The hysteria goes to the viewer. At home you can cross it and leave it alone in the room, it helps well and quickly.
In public places it is worse, there will definitely be a heart-healthy person who will pour oil into the fire with his swallowing, and the child who is beating in convulsions will have to be quickly evacuated to a more deserted place.
Children, like animals in a herd, try to find their place in the family hierarchy, and will fight for it in the ways available to them. It is up to the adults to show them the place.
And if you have seen family, only in American children's films, then I will disappoint you, in life this is not the case.