In Need of Attention
You don't want to mess with Kevin McCallister.
This guy can go from cute kid to villain-from-Saw at a moment's notice. He can act innocent and adorably bratty around his parents, before unleashing the booby traps on his burglar enemies. (Actually, if you have time, check out this article, which makes a convincing argument that Kevin grew up to become Jigsaw from the Saw horror series. We're just throwing that out there.)
In the course of Home Alone, Kevin goes from being a whiny little brat to a hardcore survivalist to an Avenging Fury, smiting down the enemies of the All-American Christmas.
At the beginning, he craves attention. Given that he's a little kid—he's only eight years old—this is understandable. But his family is preoccupied with preparing for their big Christmas trip to France, so it's a bad time for Kevin to be demanding this kind of attention. It doesn't help that his brother Buzz just scarfed down a cheese pizza ordered specifically for Kevin, or that his Uncle Frank won't let him watch the violent movie Angels with Filthy Souls…even though it's not even rated R.
Kevin's attempts to assert himself, attacking Buzz over the pizza thing. This just irritates everyone else in the family. He gets banished to attic bedroom, wishing his family would disappear.
KEVIN: This house is so full of people it makes me sick! When I grow up and get married, I'm living alone! Did you hear me? I'm living alone! I'm living alone!
Kevin soon gets a taste of this solitude and discovers it's not all that it's cracked up to be. But we're getting ahead of ourselves.
He Ain't Nothin' to Play With
After Kevin's family accidentally leaves him behind as they go to France (he thinks he made them disappear through a magical wish), he's initially excited. He's king of the castle—with total free reign. He gets to eat all the ice cream he wants, ride a toboggan down the stairs, and watch Angels with Filthy Souls, the (horrible sounding) movie that his obnoxious uncle denied him.
But, gradually, the need to survive overcomes the thrill of his own liberty. Ultimately, he's not purely free, because without his family around, he has responsibilities: he has to buy his own food (like a microwaveable TV dinner) and his own toothpaste. He even purchases fabric softener. Under pressure, Kevin learns how discover his competent inner hero, and his brattiness starts to subside.
Look at how deftly he handles the nosy (but rightfully concerned) lady who checks out his groceries when he goes shopping:
CHECKOUT WOMAN: Are you here all by yourself?
KEVIN: Ma'am, I'm eight years old. You think I would be here alone? I don't think so.
At other times, his immaturity gets the best of him. He thinks his neighbor, Mr. Marley, is a serial killer, and runs out of the drugstore when Marley enters, inadvertently stealing a toothbrush in the process. His childish fears are also evident in his fear of the basement, where he imagines the furnace morphing into a monster.
Hey—he's only eight.
Little Kid Becomes Big Kid
But gradually, Kevin gets a better handle on his reactions and he's able to conquer his fear of the basement. Just in time too, because he's got another challenge to face: burglars Harry and Marv (who are just as sleazy as they sound) are creeping around his house and plotting a big break-in. Kevin puts his imagination to work and uses clever ruses—involving a violent VHS tape movie and the silhouette of a Michael Jordan cardboard cut-out—to keep the burglars at bay.
Of course it can't be that easy, and he can't hold them off permanently. He discovers when they're planning on coming back to rob the house, and vows he'll be ready. He's at a point now where taking on a pair of bumbling burglars doesn't seem so far-fetched.
Also in line with this newfound maturity, Kevin realizes Mr. Marley is one of the good guys—or at least that he's definitely not a serial killer. Listening to a choir in church, he and Marley talk to each other, and Kevin urges Marley to reconcile with his estranged son so he can spend Christmas with his granddaughter.
At this point in the story, Kevin's been through a lot. He's realized that he really does want his family back, even though he's capable of surviving without them. See what he tells a Santa impersonator (who works at a Christmas display place):
KEVIN: This is extremely important. Will you please tell Santa that instead of presents this year, I just want my family back. No toys. Nothing but Peter, Kate, Buzz, Megan, Linnie, and Jeff. And my aunt and my cousins. And if he has time, my Uncle Frank. Okay?
Even Uncle Frank gets a shout-out. You know Kevin's lonely if he misses Uncle Frank.
Search and Destroy
So, Kevin's developed as a person. His brattiness has entirely subsided, and he's a seriously competent dude now. But he still has to deal with the burglars…
Finally, the storm of ultra-violence ensues, and Kevin blasts the burglars with a BB gun before leading them through a house full of booby traps. This leaves Marv with a nail in his foot and the imprint of a clothing iron on his face. Harry gets a burned head and hand, and other injuries besides. Kevin's showing them exactly what he's made of: iron.
We realize that he's no one to mess with. He will mess you up. He is the one who knocks.
After being rescued by Marley—who bashes the burglars with his snow shovel, and hands them over to the cops—Kevin waits to see if his family will return. The next day, on Christmas, they do. His mom gets there first, having gone through her own personal journey to reach him. Then, the other family members pour in, having taken a flight she didn't want to wait for.
Kevin impresses everyone with his survival skills, even though he doesn't reveal the truth about the burglars. His transformation complete, all he has left to do is observe the results of his actions coming to fruition.
With Kevin's encouragement, Marley reunites with his son's family, and Kevin waves to him from the window. Kevin's not only gained the ability to help himself, but also to help other people around him. When Buzz flips out because Kevin destroyed his room while he was gone, we sense that Kevin will be more than competent in dealing with him…hopefully.
Let's just hope he doesn't burn Buzz with a blowtorch or drive a nail into his foot.