How Casey’s Past Protected Her From The Beast In Split

Her Trauma Echoed In The Beast’s Shared Memories

While the film is ostensibly concerned with Kevin’s past, the person whose backstory is elaborated on most explicitly is Casey’s. She’s introduced as the weird kid who’s always on her own and constantly getting into trouble, only invited to the birthday party from which the girls were kidnapped out of pity. Despite these social defects, she shows a proactiveness and understanding of the dire situation that allows her to succeed where the others fail.

The truth behind this, however, is rather haunting. In a series of flashbacks, audiences see her being taught to hunt by her father, at first ᴀssumed to be the cause of her skewed view of the world, but later revealed as context for the horrific abuse at the hands of her uncle. The film provides a chilling representation of pedophilia — the grooming scene, with the adult wanting to “play animals” is terrifying, as is the power the uncle wields even when held at gunpoint — and goes to great efforts to show how it affected Casey’s life growing up.

The story resolves itself with Casey finally finding the power to talk about her experiences, a decision in stark contrast to Kevin. Rather than letting a troubled past manifest, she chooses to deal with the problem, which ties directly into the film’s core theme. It’s a theme that continues in Glᴀss, the final movie of the trilogy.

Split’s Themes Of Generational Abuse & Trauma Explained

How Casey And Kevin Deal With Their Pasts Affects Their Futures

On a thematic level, Split is predominantly about how people deal with abuse. Both the protagonist and antagonist are the product of turbulent childhoods that have led to them becoming outsiders. For Casey, this manifests in her desire to be alone, with silence essentially her coping mechanism — she causes trouble so she can be sent to detention and get away from everyone. Kevin’s is a more extreme case, hinted to come from a darker past, where he’s completely repressed the pain and birthed new personalities to cope with his trauma.

There’s an interesting connection between those “damaged” people. Casey uses her vague grasp of Kevin’s mental fracturing to try and help herself escape while the other hostages can’t concentrate. Later, the Beast doesn’t kill Casey because he sees her self-harm scars that show him she’s similar to him. It’s a brutal but strangely poignant reflection on how people suffering from mental health issues can view themselves as alone, not seeing their connection to the wider world. This ties into the bigger solution to this insular thinking that the director presents; finding and accepting the compᴀssion and understanding of others.

Throughout the movie, Kevin is offered empathy from Dr. Fletcher despite the mocking from her neighbors and peers, but the Dennis personality keeps ignoring it, willingly leading him down the dark Beast path – literally finding comfort in only himself. In contrast, Casey learns to address her past, making an active move against it and starting herself on a better trajectory. It’s a rather simple notion, but a well-meaning one. The film preaches acceptance and openness, both to oneself and to others.