One thing I hear a lot of online is the refrain that today's audiences are more sophisticated (or, in deference to The Simpsons, "sophistimacated"); so that when we, sophistimacated as we are, read an old story with a simple twist, it's common to hear "oh, maybe that surprised them back then." (Other variations include "maybe that entertained them back then, before they had the internet.")
To some extent, that might be true; it's hard to imagine "and the villain was the evil split personality" being much of a twist anymore. Similarly, most readers today wouldn't be surprised when the end of this story reveals that there is no Charles in this kindergarten class and that all the mischief is probably traceable back to Laurie.
But although the parents in this story never guess that, there are so many clues throughout that it's hard to imagine that Jackson was going for a true "shock the audience" twist. The very first sentence of this story notes that Laurie is changing, "my sweet-voiced nursery-school tot replaced by a long trousered, swaggering character...". And when he comes home, he's fresh and naughty all over the place. So this story--another of Jackson's domestic slice-of-life tales--doesn't try to shock us with Laurie's naughtiness; what's more shocking is that the parents (including the narrator) don't get it.
What's especially shocking--if you don't have kids--is how ordinary this sort of terror can become:
Wednesday and Thursday were routine; Charles yelled during story hour and hit a boy in the stomach and made him cry.Sure, there's a Gothic touch here, with the phantom bad character and the adults drawn in to the mystery (what's Charles's mother like?). But it rubs up (again) with that sense of the ordinary and domestic. Jackson's other works may involve haunted houses; her autobiographical and domestic stories show us that all houses are haunted.
(Is that true? Or does it just sound good?)