Outbursts are not OK
As we make a healthy move away from our traditionalist past of pressuring children to hide their feelings, we must be careful not to swing toward an equally unhealthy “progressive” present that says a child’s emotions are always welcome, whenever and in whatever way he or she wants to share them. As Haim Ginott notes from a group conversation with parents:
We can recognize that the child has hateful feelings, and we will help him to express them only in certain ways and at certain times. Thus we can tell the child, "We want to hear how you feel. But we will not tolerate your showing your resentment by slamming doors when your great-aunt Patricia's here. There's a better way of doing it and a better time and place."