Film Theory: How IT Explains The Secret Of The Shining
6. They Happen In The Same Universe
Evidence is obviously a key thing when setting out theories like this and as a starting point, we know that The Shining and It happen in the same universe. They're linked by the presence of Dick Hallorann, who obviously plays a major part in The Shining as another character who possesses Danny's powers.
He's also mentioned in It as an Army cook who was present when Derry nightclub "The Black Spot" was burned down by the Legion of White Decency in 1930. Thanks to his powers, he was able to save the lives of other clubgoers, including Mike Hanlon's father. He is also capable of seeing It in one of its varying forms while remaining sane as an adult.
The fact that he plays a part in both stories should really say something.
5. It Feeds On The Torrances' Fears
Obviously, the key element of It's relationship with its victims is how it feeds: it inspires fear in them as a sort of flavour enhancer - the idea of fear "salting the meat". And while It is associated primarily with feeding on children, it will feed on any human, it just so happens to find that children are easier to manipulate and prey on.
But that's not true in The Shining, because in Jack Torrance, It is presented with a far more simple target than Danny. He comes there already vulnerable, having lost his teaching job because of his alcohol dependence and drug abuse, injured his son in a rage and on the verge of being left by his wife. He teeters on the edge of his worst fears - of being abandoned by his family and seeing his career go to ruin. In short, he's already seasoned well for It.
And as his fears take him over, It manipulates him into doing his dirty work - killing his family, to get more victims in one fell swoop, which in itself inspires a further escalation of Jack's conscious fears. It turns him into everything he feared he would be and drives his family away, making him an even more delicious potential meal.
Not only that, It scores a double success by using Wendy's fears - that Jack cannot be turned away from his path that leads to him being a monster - against her too. Ultimately, she resists as her fear that more harm will come to Danny trumps her owbn crippling fears, but it could go either way right up to the end of the film.