The question of whether or not the governess Miss Giddens (Deborah Kerr) of the 1961 movie The Innocents, directed by Jack Clayton and based on Henry James's 1880 novella, The Turn of the Screw, is a pretty hot topic. Some say that she was just crazy, while others state that she really does see the ghosts for varying reasons. I personally feel that she does see the ghosts for the sole reason that she describes them to Mrs. Gross (Megs Jenkins) without having had any prior knowledge of who they were, what they looked like, or where they died, which in the case of the last governess, Miss Jessel (Clytie Jessop), the present one viewed her in near her watery grave of the lake in the movie.
There have been many authors who have tried to describe the vision of spirits in many different forms. One such author is Anne Rice, who wrote such novels as Merrick, Interview with the Vampire, and The Witching Hour. In her latest novel, Blackwood Farm, the subject of ghosts is addressed. As she explains it on a scientific level (and please note that this book is fiction, and therefore its theories hold little weight in the real world) certain people can see ghosts. So perhaps the governess has a special gene, such as is the case with Tarquin Blackwood, the character in Anne Rice's novel, which entitles her to see ghosts, whereas the rest of the people in the house do not carry this gene and therefore could not view them. It would certainly explain way the governess could see them, whereas nobody else seems to be able to do so.
Whether the children, Miles (Martin Stephens) and Flora (Pamela Franklin), really see the ghosts or not, that cannot be clearly stated. Like Anne Rice's Tarquin Blackwood, who can see the ghosts yet is not sure if anyone else can and often speculates on just this subject, perhaps the governess feels the same way. Since she can see them so clearly then so should over people. Yet like children looking at the clouds to find animals, we cannot all see the same thing.