The Joker is a villain that both fascinates and terrifies us. His origin has remained relatively mysterious, sparking questions about how a “psycho killer” is created. Using real methods and theory, clinical expert Dr. Andrea Letamendi examines several iconic portrayals of the Clown Prince of Crime. Given the raised concerns causing tension to surround the new film, Joker (2019), considerations are given to the science behind behavioral threat assessment, case study, and occurrences of real events in an effort to responsibly inform the discourse.

The author wishes to note to readers that this collection of psychological profiles includes some references and descriptions of both real and fictional portrayals of mass violence, intimate partner abuse, and suicide. Just like the Joker, these conceptualizations are fictional and are not meant to diagnose any real person. This series is not intended as a substitute for the medical or mental health advice of psychiatrists or other clinical professionals.

The Performer

Jack Nicholson’s performance in Batman (1989) successfully captures the indelible, recognizable personality characteristics of the Joker from the comics: He is an eccentric criminal with a sadistic sense of humor. Nicholson, however, amplifies the traits most concerned with ego: A ballooned sense of self, an overt grandiosity, and the inability to tolerate others in the spotlight (i.e., Batman “stealing his press”). This Joker is larger than life – and requires an audience. His bright purple suits are well-coordinated and impeccably tailored. His bold, perfectly set clown makeup draws all eyes to him. When we see Nicholson sashay through the Flugelheim Museum, laughing wickedly beneath his silk beret to Prince’s “Partyman,” we can’t help but respond the way Vicki Vale does: Freeze in disbelief at the spectacle but keep watching.

The Joker’s narcissism is closely tied to his propensity for violence, in that violence is the solution or mechanism used to regain power, control, or notoriety. He is playing a game in which he methodically upholds trust and loyalty only as operative tools; connections with people are formed only to retaliate with abuse and emotional terror. Often, this is played out as an enactment– the idea that he can create destabilizing fear in others is, in his mind, performance art. In the Joker’s words, “I make art until someone dies.” For instance, after making a promise to give twenty million dollars away to citizens who attend Gotham City’s 200thAnniversary Parade, the Joker sends his army of goons to amass the event. Atop his ostentatious float (and, again, showcasing), he and his henchmen surprise the city by attacking event-goers with the lethal gas, Smylex, a compound the Joker engineered from a discontinued nerve gas used in war. Though it is unclear how many innocents died, this act of social, widespread terror carries an undeniable similarity to mass violence observed in our current, nonfictional reality.

For many violent perpetrators, the idea of being observed during a grand act is an instrumental part of their idealized self (the person they want to be); getting their name on the news is powerfully motivating. Were this today, Joker would have Facebook-lived the parade attack. An exploration of the Joker’s motivations and propensities therefore requires some consideration of what we know about real violent criminals.

Essential Traits of the Joker

The most effective Joker portrayals seem to be able to capture the same core or “recognizable” traits in their characterization. The following five personality and behavioral traits could be deemed as fundamental to the Joker’s psychology:

1. Fixation with chaos. The Joker has a preoccupation with the social order, as well as how he functions in that system as an anarchist. In Nicholson’s portrayal, this manifests in the form of defacing art, disrupting board meetings, and orchestrating a choreographed pantomime show during a live broadcast. Nicholson’s Joker is perfectly placed in the 80’s, an era known for its indulgence and ostentation. The tastes of the upper echelon were represented in fashion, music, and fine art, all demonstrations of creativity but exclusively reflecting the dominant wealthy. The biggest perceived threat during this pre-Columbine era was not attacks by active shooters, but the overt disruption of capitalism. An L.A. Times article written the week of Batman’s theater release reveals the shared displeasure among critics of Nicholson’s anarchist portrayal through the lens of a museum director. He feared the Joker would prove to be a “powerful symbol to sub-literates” who may emulate his dangerous behavior. The focus of concern was the art museum scene, not the parade.

For the Joker, subverting the social order means hijacking and subsequently amplifying what is culturally constructed as “refined” and making it silly, grotesque and self-consciously artificial and extravagant. Tampering with the city’s cosmetic products by lacing them with the lethal, mutilating compound Smylex is another example of Joker’s attempts to transfigure and appropriate what society values as beautiful. Similarly, the Joker evidently disfigures his ex-girlfriend, Alicia, in order to call her “a living work of art.” When he forces himself into Vale’s apartment, the Joker comments on how nice (i.e., valuable) the place is, but fixates his eyes on her crotch when he says, “lots of space.” Like the paintings in the Flugelheim, women are visual artifacts, and therefore can also be defiled.

Importantly, based on what we know about violent criminals, a fixation on social chaos may also be experienced as homicidal ideation, especially toward figures who represent lawful order or status quo. For the Joker, his fixation does take on violent themes, but the fixation actually amplifies around a person or idea – in this case, Batman.

2. A propensity for violence and homicide. Violent preoccupations (thinking about and planning violent acts), acquiring weapons, and having the capability of following through on hostile, homicidal ideas are marked features of the Joker. This is the most concerning feature. Generally, there are two different motives among violent criminals. “Impulsive violence” is typically unplanned and is provoked, whereas “predatory violence” is instrumental, calculated, and targeted. Nicholson’s Joker aligns with criminals who use the mode of predatory violence because the majority of his actions are premeditated and controlled. In fact, he glibly announces his plan to poison Gotham’s citizens on the news in the form of a bizarre advertisement for Smylex. Like sending letters to the press or tweeting a vague threat, this release of tension is known as “leakage” and is considered an antecedent to severe violence.

3. Sensation-seeking. There is a myth that people who hurt others are unfeeling. Though non-experts compare the Joker to unemotional psychopaths, he is almost always portrayed as a visceral, passionate character with very salient feelings. In fact, in Nicholson’s portrayal, there seems a connection between violence and pleasure. What is arousing for this Joker isn’t the violence itself but the meaning of the violence. Through destruction, he gains power, dominance, and the delicious spotlight. But there seems an added boost of adrenaline, as if the risk-taking itself fills his brain with feel-good chemicals. When he points his pistol at Bruce Wayne in Vicki Vale’s apartment, Joker is rather calm and composed – it is a reflex, but doesn’t seem as rewarding. This action isn’t comparable to the euphoric sensation he experiences during his reckless dancing atop the unstable Gotham Cathedral roof, where his risk of falling to death is as equal to his adversaries, Batman and Vale. Here, he is in his element. People who crave and seek adrenaline will often engage in highly risky behavior, which leads to higher chances of injury, accidental, and intentional death. This is because over-arousal elevates physical pain tolerance and interacts with a sense of fearlessness about death, which can push someone over the edge of self-control. In other words, through repeated exposure to his own hijinks, the Joker habituates to the physically painful and fearful aspects of risky behavior, making it possible for increasingly painful, physically damaging, and lethal forms of self-harm. In fact, nearly half of real-life killers are suicidal prior to their attacks on others. It’s possible that the Joker carries suicidal desires and may want to die by his own hand.

4. Charisma. Though the idea is taboo, many people find the Joker appealing. Whether felt as admiration, physical attraction, or even infatuation, the allure is real. Nicholson’s Joker tends to be well-dressed, sophisticated, and flirtatious. However superficial, this charm can be effective in pulling others close to him. As he evolves in the film, his Joker-esque qualities actually intensify. Shortly after his transformative accident at the Axis Chemicals plant, he begins to experiment with his new persona; over time, he actually develops a stronger “identification” with the concept of himself, and subsequently more extreme and horrific acts. That is, if what he thinks about all the time is himself, he begins to behave in ways that confirm those beliefs. This is often how someone who engages in torture may go on to murder. His preoccupation with his identity is in fact a risk factor that may lead to increasingly more dangerous behavior. For Nicholson’s Joker, performative theory confirms this concept: his views actions, behaviors, and gestures are certainly the result of his own identity but also play back inward in forming and defining his identity. By the end of the film, these attributes – charisma, violence, chaos, and narcissism—are all amplified.

5. Lack of empathy. The Joker has a striking sense of entitlement, coupled with a concern for others’ rights and feelings. Though it isn’t considered a psychiatric diagnosis, the use of “psychopath” refers to someone who does not take responsibility for their actions – this is an individual who has callous disregard for others and intentionally exploits people close to them. For the Joker, this feature is inextricable with his interest in chaos: Lacking remorse for wrongdoing leads to an escalating pattern of violating policies or laws. Nicholson’s Joker holds a “black and white” style of thinking, such that someone is either with him or against him. The line is very fragile – beneath the seemingly confident veneer is an incredibly vulnerable human. It’s startling to see him kill his “number one” henchman, Bob, with such abruptness. When killers experience a disparity between the actual self and the ideal self (e.g., due to a failure), a violent act is typically the solution to ease that tension. Poor Bob became the (nearest) target when the Joker’s plan to poison Gotham’s citizens was thwarted by Batman. His preoccupation with negative felt insults, coupled with his vindictive and extreme envy of others, create significant risks for such impulsive violence.

Jack Napier

Prior to Joaquin Phoenix, Nicholson’s Joker is thus far the only version that fills in some meaningful biographical gaps in his narrative (and not retold from his potentially unreliable point of view). Not much is revealed about the developmental, social, environmental, or genetic factors that may have shaped Jack Napier’s anti-social personality. But Batman’s terse review of Jack’s “case history file” results in us learning about some key facts. Jack was accused of assault with a weapon at age 15. His skills in chemistry and art at a young age are notable. Presumably, the file was charted prior to the Joker’s birth, with terms such as “unstable” and “highly intelligent” clueing us into pre-existing personality deficits. Before his transformation, Jack exhibited a number of concerning behaviors and propensities that would be considered risk factors for mass violence. In fact, it is likely that any stressful event such as a near-death experience, trauma, or significant loss would operate as a catalyst for The Joker to emerge.

Jack is uncaring, uncompassionate toward others, and entitled. His identity is completely defined by his exterior appearance, and although he appeared confident, his sense of self was actually quite fragile and easily threatened.

People do not “snap,” but they can be pushed by circumstances. Jack was already corruptive, dishonest, and willing to kill, but he did not yet exhibit extreme moods or euphoric pleasure from violence. As Joker, he would develop periods of extreme agitation, anger or acts of violence associated with the intense emotionality we see at the end of the film.

A Triggering Event

During the Axis Chemicals heist, Jack is marred by a shot from his own gun and knocked into a vat of toxic chemicals. He survives, and even underground reconstructive surgery cannot restore his face. This is the turning point for Jack, the moment his anarchism and mass violence begins. There are many “types” of triggering events that can lead to mass violence, but one in particular, known as a retraumatizing event, can give a person a strong sense of retaliation. He already felt exploited and disgraced by Carl Grissom. Napier interprets the setup at Axis (and the resulting disfigurement) as an experience that legitimizes his pre-existing, vengeful ideation. “I am victimized again; I am morally outraged again, and therefore must take matters into my own hands.”

Incidentally, mass killers often experience a retraumatizing event before their behaviors escalate; their beliefs of victimization are reinforced and often lead to formations of planned attacks and killings. Shortly before murdering him, the Joker tells Grissom, “Jack is dead…call me Joker,” to announce his new self. He has come back to life; an extreme version of Jack, with his new identity giving him full permission to follow his pre-existing impulses.

Target Dispersion and Batman as the Accelerant

The Joker experienced a significant grievance in the form of his colleague’s betrayal – but what was more damaging to his ego was the humiliation experienced as a result. Of consideration is the significant “loss of the self” and damages to critical parts of his identity: beauty, charm, and power. But why didn’t his grievance end after murdering Grissom? One explanation comes from the concept of “target dispersion,” which refers to hostility felt toward one person (here, mob boss Grissom) that can be so intense that it spreads or “generalizes” to an entire group of people.

The Joker feels compelled to move on to others who represent or participate in any way in Gotham’s corruptive economic, social and political elitism. Identifying “threat enhancers” is crucial to minimizing danger and re-establishing safety. Bruce Wayne, undoubtedly, is a contributory figure given the symbology of his socioeconomic status. Wayne’s involvement in the story actually accelerates Joker’s behavior toward increasingly more violent and risk-taking actions.

Untangling the Madness

Mental health experts do not recognize any single psychiatric diagnosis as equivalent to “violent killer.” An interest in targeted violence is, in itself, considered alarming and problematic. But mental health is not generally named as a root cause of murder. As mentioned, the usage of the term psychopath (which is not a clinical diagnosis) may be the most suitable term for the Joker. Psychopathic traits include features of callousness, manipulation, selfishness, violation of social norms, and the need for stimulation. However, to make matters even more complicated, none of these characteristics are really any good at predicting lethal violence. Above all else, the single most compelling risk factor for future violence was Jack Napier committing assault with a deadly weapon at the age of 15.

A pattern of escalation, coupled with a history of cold murder, is perhaps the most concerning formula presented by Nicholson’s Joker.

The Joker’s “performance” can be interpreted either as “breaking down” of his perceived reality, or as the “ramping up” of his extreme, euphoric mood states to fatal levels at the climax of the film. His performance endures: As Joker dances atop the crumbling terrace of the Gotham City Cathedral, it does not matter that Vicki Vale is not a participant, that she’s unwilling and non-consenting. He’s reached the peak of his self-absorption; his performance is for all of Gotham City to witness and simultaneously, only for himself. As he thrusts atop the crumbling bricks, his recklessness increases and his inhibitions break down. Even as he clings on to the rope ladder the emotions seem a mixture of fear, wonder, thrill – and when he shrieks, “Sometimes I just kill myself!” his admission is an openness to any outcome, as long as it involves excitement. His death is an acceptance that this pattern is unsustainable and that he has pushed himself past his own limits. Tragically, the Joker reaches the point of no return and must let go completely.

Click below for our psychological profiles of several other iconic versions of the Joker and Harley Quinn: