We have taken our son on Haunted Mansion since he was several months old, and he personally has not had a problem...I think he has been conditioned to it for so long.
A BETTER STORY is from my childhood. My entire family (parents and 4 children) were going on Haunted Mansion. My father decided to put my youngest sister, probably 2 ½, on his shoulders...you know how cramped it can get in the foyer and the stretching room on a busy day. Well, she had a great view of everything in the portrait gallery, and then my father had the brilliant idea to say, "Caroline, look up", just at the point when the skeleton is hanging in the rafters. Well, apparently, she was so scared she wet herself, and needless to say, my father.
We still think of this as on of our funniest disney moments. I do remember my father got a new Mickey Mouse sweatshirt out of the deal. I don't think she rode on his shoulders on that attraction anymore.