Our 3 year old son has recently started having horrible tantrums when he does not get his way. I have read your site and we have been putting him in his room to calm down but have not yet installed the Dutch door. I read today in one of your responses that children his age are "terrified" of being locked in a room alone, which is what we have been doing when he starts hitting/kicking/pinching/biting/pulling hair. I'm worried I have screwed up because we don't yet have the half door. When he gets violent I have started putting him in his room and locking the door until he calms down. We are never far away. Otherwise he will open the door and walk out. have I messed up or is this okay? It seems to helps him calm down more quickly. He does not have these episodes at school (he goes 3 days/ week) just with us at home. Taking away toys seems to have no impact. And the tantrums can go on for an hour or more.