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The Science Behind "Dexter": The Psychology of a Survivor

Megan Kathleen created her own fear and avoidance hierarchy in order to manage social anxiety.

"Dexter" is a show loaded with psychological elements.

"Dexter" is a show loaded with psychological elements.

A Story About a Boy

Dexter is a story about a very particular serial killer. Its titular character methodically tracks his victims, ensuring that they meet his code before they wind up on his table; Dexter Morgan only tracks and kills other killers to ease the burden of his psychosis. Though Dexter primarily focuses on the mental wanderings of its dark hero (the show is studded with voice-over commentary that delves into his state of mind), the mental lives of other characters are also fraught with psychological complications.

Here we look at the symptoms of Post Traumatic Stress Disorder that are displayed by both Deborah and Dexter Morgan following their final encounters with the Ice Truck Killer.

309.81 DSM-IV Criteria for Posttraumatic Stress Disorder

A. The person has been exposed to a traumatic event in which both of the following have been present:

  1. The person experienced, witnessed, or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others.
  2. The person's response involved intense fear, helplessness, or horror.

The Traumatic Event

Brain Moser meant many things to Deborah and Dexter Morgan. To Deborah, Brian was the man she had fallen in love with and agreed to marry, that is, until he kidnapped her and tried to kill her. For Dexter, he was the brother he never knew he had, the brother that he had to kill to protect his adopted sister. To the rest of Florida, Brian was the Ice Truck Killer, a man who murdered women and left them in bloodless pieces. In the end, he was dead, and both Deborah and Dexter were left with haunted memories.

Dexter's preferred tools, the Ice Truck Killer uses them to incapacitate Deb.

Dexter's preferred tools, the Ice Truck Killer uses them to incapacitate Deb.

DSM-IV Criteria (continued)

B. The traumatic event is persistently reexperienced in one (or more) of the following ways:

  1. recurrent and intrusive distressing recollections of the event, including images, thoughts, or perceptions.
  2. recurrent distressing dreams of the event.
  3. acting or feeling as if the traumatic event were recurring (includes a sense of reliving the experience, illusions, hallucinations, and dissociative flashback episodes, including those that occur upon awakening or when intoxicated).
  4. intense psychological distress at exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event.
  5. physiological reactivity on exposure to internal or external cues that symbolize or resemble an aspect of the traumatic event.

Trauma Relived


Deborah has to come to terms with many thoughts after her capture and escape from the Ice Truck Killer. Not only had her life been in danger but also she had been betrayed by the man she loved. At first she tries to avoid her emotions, but six weeks later she is back at work and surrounded by constant reminders.

"I saw the man I thought I loved. No, did love, up on some god damn screen with a gallery full of women that he murdered and cut into pieces... So how am I doing? I'm just fine," she explains tearfully to her brother ("Waiting to Exhale," Season Two, Episode Two). The police department is finalizing the details on the Ice Truck Killer case while ramping up to investigate the Bay Harbor Butcher (Dexter, whose dump site has been found) so her emotions are close to the surface.

The physical reminders startle Deb more than the emotional ones. Out at a bar with Rita, Dexter's girlfriend, a man recognizes her and touches her on the shoulder. Instantly she whirls around and punches him in the nose, a defensive gesture born from the need to not be restrained as she had been. Similarly, an attractive man at the gym offers to tape her hands to protect them while boxing, but the sound of tape being unrolled causes her to spook.


Dexter claims to be emotionless, even believes himself to be, but the act of killing his brother distresses him enough to affect his routine. "I'll be okay. I followed the code. My stalk was good. I'm just a little rusty since killing my brother," he reasons after attempting to kill a murderer only to find his knife missing its mark ("It's Alive," Season Two, Episode One). Reliving the killing stroke causes Dexter to pause, unable to continue.

This theme continues, as Dexter shakes and cuts too much when he has Little Chino on the table. Dexter knows his inability to kill is related to the death of his brother: "39 days, 22 hours, 18 minutes since I killed my brother. I am cursed" ("It's Alive," Season Two, Episode One).

Dex is haunted by the ghost of Brian, literally. He hallucinates talking to Brian at work and in church. This is something with which Dexter has struggled before. He constantly envisions talking to his dead surrogate father, Harry, which could have something to do with reliving another traumatic experience: as a child, Dexter witnessed the brutal murder of him biological mother.

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DSM-IV Criteria (Continued)

C. Persistent avoidance of stimuli associated with the trauma and numbing of general responsiveness (not present before the trauma), as indicated by three (or more) of the following:

  1. efforts to avoid thoughts, feelings, or conversations associated with the trauma
  2. efforts to avoid activities, places, or people that arouse recollections of the trauma
  3. inability to recall an important aspect of the trauma
  4. markedly diminished interest or participation in significant activities
  5. feeling of detachment or estrangement from others
  6. restricted range of affect (e.g., unable to have loving feelings)
  7. sense of a foreshortened future (e.g., does not expect to have a career, marriage, children, or a normal life span)



Much to her dismay, Deborah is chosen to work on the task force in charge of catching the Bay Harbor Butcher. She is put to work interviewing families of missing people to find possible leads on the identities of the victims. We see her speaking with a woman who is desperately seeking her loved one, a man who, like Brian, was thought to be dangerous. Immediately after this interview, Deborah asks to be off the task force.

When Special Investigator Frank Lundy fails to heed her request, she explodes: "Jesus, I just don't want to be on your task force, alright?... Because I'm the last person in the world that should be on it. You want me to find a serial killer? I was engaged to one, for Christ's sake!" ("An Inconvenient Lie," Season Two, Episode Three). Lundy implores her to remain, to use her knowledge of serial killers for a greater purpose. Essentially, he tells her "to stop running," because that is what she is doing, trying to run away from any reminder of her past ("An Inconvenient Lie").

DSM-IV Criteria (Continued)

D. Persistent symptoms of increased arousal (not present before the trauma), as indicated by two (or more) of the following:

  1. difficulty falling or staying asleep
  2. irritability or outbursts of anger
  3. difficulty concentrating
  4. hypervigilance
  5. (exaggerated) startle response

Source: Mental Health Today

Arousal (Not the Pleasant Kind)


The first time we see Deb after her experience with the Ice Truck Killer, she is living with Dexter. He comes home late after an aborted kill attempt to find his door locked and his sister on the treadmill. "Deborah can't sleep in an empty house anymore. In fact, she can't sleep much at all. I guess that's what happens when your fiancé tries to slice you up into small, bloodless pieces" ("It's Alive", Season Two, Episode One). She cannot sleep and uses exercise as another way of separating herself from her emotions. She also is hypervigilant and easily startled, as evidenced when Dex attempts to enter his own home and finds the bolt slid against him. Deborah jumps at the sound but lets him in once he identifies himself.

Deborah not only works out at home but also at the gym. Excessive exercise does not seem to be enough for her, so she tries to take out her aggression on a boxing bag.

Deb's aggression comes out when she punches the guy at the bar, but that is in response to his touch, a physical reminder of her trauma. What is worse is when Deb pulls a gun on a kid who tags her car. The response is completely out of context, and Bautista has to yell at her repeatedly before she backs down.


Deborah is not the only losing sleep at night. Dexter lies awake as well. His sleeplessness stems more directly from his inability to concentrate, another sign of PTSD: "Where is the orderly, controlled, effective Dexter?" he wonders, "How did I lose him? How do I find him again? I'm drifting...but not to sleep" ("Waiting to Exhale," Season Two, Episode Two).



"There's bodies in those bags. Did you hear that? Thirty bags, do you know what that means? It means there might be a new masked murderer out there way worse than the Ice Truck Killer. Maybe I can finally get some peace. Isn't that great?" ("It's Alive," Season Two, Episode One).

When Deborah first hears of the Bay Harbor Butcher, she recognizes it as a chance to heal from her experiences, but she cannot take that change alone, as evidenced by her avoidance behavior. It is Agent Lundy's influence that ultimately saves her. He recognizes her pain and struggle and attempts to use it for the good of his investigation, and ultimately Deb herself:

"It's why I chose you, you know. Because of what you went through. You survived. I don't know how. I can't begin to imagine the strength it took. Continues to take. More than that, you got a first hand look into the mind and heart of a killer. And you're still here. If you can accept that, really accept it, you could use it. Mix that with some of your strength, and you can catch someone even worse than the Ice Truck Killer. But you have to stop running." ("An Inconvenient Lie," Season Two, Episode Three)

Deb throws herself into her work while also attempting a relationship with the man she met at the gym. She still has trust issues and irrational responses to stimuli, but the act of finding something else to occupy her time that also helps her face what she experienced by exposing her to it allows her to move on in time.


Dexter's recovery from PTSD is more complicated. He manages to escape the ghost of his brother out of necessity. With the many mistakes he makes while tracking his prey, he needs to kill Little Chino before he can identify Dexter as a murderer. Dexter's problems continue in other ways, however, as he has still not recovered from witnessing his mother's murder, a possible cause of his murderous impulses (a topic too diverse to be covered in this particular investigation).

Real Life Problems

Television shows often simplify real life situations and experiences for the ease of viewing. This makes it easier to identify relevant information, such as the symptoms listed above, but the solutions offered are not always applicable in the real world. Though some people are able to deal with their mental health issues on their own, it is best to seek professional help if you believe yourself to be suffering from PTSD.

Information and Resources


Burnell Andrews from LaBelle, Florida on July 02, 2013:

For me the appeal of dexter comes from the various issues I face as a aspergers person, in a way I identify with him, figuring out how people think, putting on masks, hoping to be normal, not the psycho part but the rest of it, missing circuit that helps you connect with other people, the whole spiel. Ummm for other people I suspect it is more about the vicarious vengeance that they get against various criminals, you would call it the inner savage that civilization papers over.

I think Dexter is somewhat in a permanent state of shock from the killing of his mother, its not that he doesn't feel it is more that he is well rather numb, he just doesn't feel as strongly, but we do see plenty of times when that emotion does come out, particularly with those he has'grown quite fond of'.

Just offering my perspective but coming out of who you are, out who you are comfortable out of the psychological state thate you have grown used to is jarring, you really don't know how to deal with the new state, and the thing I like about Dexter is he reacts exactly as he would be expected to, not pleasantly or predictably.

Again I reiterate identifying does not mean I am psycho, just that I share some qualities. I like how you described Dexter's problems, he's been one of my favorite 'heros' mainly in how he faces and handles people (not the killing part I mean but social part), I will miss him in the final season.

Megan Kathleen (author) from Los Gatos, CA on September 05, 2011:

Thanks for the comment d.william! My friend recently introduced me to Dexter, and I find the social interaction aspects fascinating. Although some people may find that the show does not develop much, I think the small changes Dexter exhibits are fascinating. I actually have two Hubs waiting to be published about Lila and Dexter. And since I have caught up with last season (finally) I cannot wait until October!

d.william from Somewhere in the south on September 05, 2011:

Well written and and interesting topic. Oddly enough this is one of the most popular T.V. shows today. Are we, as a people, so hardened to violence that we actually have made Dexter a modern day hero? It is a well written show, and a cliff hanger for modern times. One of my favorite t.v. shows.

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