it's hard to leave me at a loss for words.

Sometimes I find myself fantasizing about unlimited success and power, and beauty.

I have repeatedly used deceit to cheat, con, or defraud others for my personal gain. To

be honest, I don't have much concern for the feelings of other people, or their suffering.

Doesn't sound like the Hank you know, does it?

These are all statements from the Self-Assessment measure for Personality Disorders, that lets

patients describe themselves, ranking each statement in terms of how accurate they think it is.

To be honest, you can't rely too much on this kind of self-reporting to assess what we are

talking about today because while some people who are over-confident or obsessed with power

or downright deceitful might tell you that they are, there is a certain subset that won't.

Many of the disorders that we have talked about so far are considered, "ego-dystonic"

meaning that people who have them are aware that they have a problem and tend to be

distressed by their symptoms.

Like a person with Bipolar Disorder or OCD generally knows that they have a psychological

condition and they don't like what it does to them.

But some disorders are trickier then that. They are "ego-syntonic," the person experiencing

them doesn't necessarily think that they have a problem and sometimes, they think the problem

is with everyone else.

Personality disorders fall into this category. These are psychological disorders marked by

inflexible, disruptive, and enduring behavior patterns that impair social and other functioning

-- whether the sufferer recognizes that or not.

Unlike many other conditions that we've talked about, personality disorders are often considered

to be chronic and enduring syndromes that create noticeable problems in life.

And as you can tell from these self assessment statements, they can range from relatively

harmless displays of narcissism, to a true and troubling lack of empathy for other people.

Not only can personality disorders be difficult to diagnose and understand, they can also

be downright scary. Most of the extreme and severe disorders go by names that you probably

recognize: psychopathy and sociopathy. I'm talking, like, serial killers here, mob bosses, Vlad the Impaler.

Cultures have been studying human personality characteristics for thousands of years, but

the concept of personality disorders is a much newer idea.

Much of our modern classifications of these disorders are based on the work of German

psychiatrist, Kurt Schneider, who was one of the earliest researchers into what was

then known as psychopathy and published a treatise on the study in 1923.

Today, the DSM 5 contains ten distinct personality disorder diagnoses, grouped into three clusters.

The first cluster, cluster A, includes what are often labeled simply as "odd" or "eccentric"

personality characteristics. For example, someone with paranoid personality disorder

may feel a pervasive distrust of others and be constantly guarded and suspicious while

a person with a schizoid personality disorder would seem overly aloof and indifferent, showing

no interest in relationships and few emotional responses.

Cluster B encompasses dramatic emotional or impulsive personality characteristics. For

example, a narcissistic personality can display a selfish grandiose sense of self-importance

and entitlement. Meanwhile, a histrionic personality might seem like they're acting a part to get

attention, even putting themselves at risk with dramatic, dangerous, and even suicidal

gestures. The behavior of Cluster B can be truly self-destructive and frightening, and

these disorders are often associated with frequent hospitalization.

Finally, Cluster C encompasses anxious, fearful, or avoidant personality traits. For example,

those with avoidant and dependent personality disorders often avoid meeting new people or

taking risks and show a lack of confidence, an excessive need to be taken care of, and

a tremendous fear of being abandoned. Now, in the past, and, to a great extent, today,

some of these categories have been controversial. Many researchers argue that some of these

conditions overlap with each other so much that it can be impossible to tease them apart.

Narcissistic personality disorder, for example, has many traits that resemble histrionic personality

disorder. And because of this gray area, the most commonly diagnosed personality disorder

is actually personality disorder not otherwise specified or PDNOS. The prevalence of this

diagnosis suggests that while clinicians can identify a personality disorder in a patient,

figuring out the details of the condition can be messy and difficult.

One proposed alternative for diagnosing these disorders is the Dimensional Model, which,

in essence, gets rid of discrete disorders and replaces them with a range of personality

traits or symptoms, rating each person on each dimension. So the Dimensional Model would

assess a patient not with the aim of diagnosing one disorder or another, but instead, simply

finding out that they rank high on say, narcissism and avoidance. It's a work in progress, so

with another generation, the clinical definition of "personality disorder" may evolve pretty radically.

One of the best-studied personality disorders right now is Borderline Personality Disorder,

or BPD. Borderline makes it sounds like patients are like, pretty close to being healthy, but

not quite, but that is not at all the case. BPD sufferers have often learned to use dysfunctional,

unhealthy ways to get their basic psychological needs met, like love and validation, by using

things like outbursts of rage, or on the other end of the spectrum, self-injury behaviors

like cutting or worse. People with BPD were once commonly maligned by clinicians as 'difficult'

or 'attention-seeking', but we now understand BPD as a complicated set of learned behaviors

and emotional responses to traumatic or neglectful environments, particularly in childhood. In

a sense, people with this disorder learn that rage or self-harm helped them cope with traumatic

situations, but as a result, they also end up using them in non-traumatic situations.

Although challenging for patients and clinicians alike, the good news is that some psychotherapies

have helped even the most severely suffering, repeatedly hospitalized BPD patients.

But probably the most famous well-established, and frankly, troubling personality disorder

is Antisocial Personality Disorder. Now, you've heard of this before, but maybe by one of its now

somewhat out of vogue synonyms, "psychopathy" or "sociopathy." People with Antisocial Personality

Disorder, usually men, exhibit a lack of conscience for wrongdoing, even towards friends and family

members. Their destructive behavior surfaces in childhood or adolescence, beginning with

excessive lying, fighting, stealing, violence, or manipulation. As adults, people with this

disorder are thought to generally end up in one of two situations: either they are unable

to keep a job and engage in violent criminal or similarly dysfunctional behavior; or they

become clever, charming con-artists, or ruthless executives who make their way to positions

of power. Tony Soprano would have qualified for a diagnosis, even if he wasn't nearly

as bad as, say, serial killer Ted Bundy or Vlad the Impaler, the infamous 15th century

Romanian prince who personally watched about 100,000 people get impaled or have the skin

of their feet licked off by goats.

Yeah. That happened.

Despite this classic remorselessness, lack of empathy, and sometimes criminal behavior,

criminality is not always a component of antisocial behavior. Certainly many people with criminal

records don't fit that psychopathic profile. Most show remorse, love, and concern for friends

and family. But still, although anti-social personalities make up just about 1% of the

general population, they were estimated in one study to constitute about 16% of the incarcerated population.

So, how might someone end up with such a disturbing disorder? Well, as you might expect, the causes

are probably a tangled combination of biological and psychological threads, both genetic and environmental.

Although no one has found a single genetic predictor of Antisocial Personality Disorder,

twin and adoption studies do show that relatives of those with psychopathic features do have

a higher likelihood of engaging in psychopathic behavior themselves. And early signs are sometimes

detected as young as age three or four, often as an impairment in fear conditioning, in

other words, lower than normal response to things that typically startle or frighten

children like loud and unpleasant noises. Most kids only need to get burned by a hot

dish once to know to stay away, but kids who end up displaying Antisocial Personalities

as adults don't necessarily connect or care about the learned consequences when they're little.

From there, like we've seen in other disorders, genetic and biological influences can intersect

with an abusive or neglectful environment to help wire the personality in a peculiar

and damaged way. While the vast majority of traumatized people don't grow up to be killers

or con-artists, genes do seem to predispose some people to be more sensitive to abuse or trauma.

Meanwhile, studies exploring the neural basis of Antisocial Disorder have revealed that

when shown evocative photographs, like a child being hit or a woman with a knife at her throat,

those with psychopathic personality features showed little change in heart rate and perspiration,

as compared to control groups.

And the classic antisocial lack of impulse control and other symptoms have also been

linked to deficits in certain brain structures. One study compared PET scans from 41 people

convicted of murder to those of non-criminals and found that the convicted killers had greatly

reduced activity in the frontal lobe, an area associated with impulse control and keeping

aggressive behavior in check. In fact, violent repeat offenders had as much as 11% less frontal

lobe tissue than the average brain. Their brains also responded less to facial displays

of stress or anguish, something that's also observed in childhood, so it's possible that

some antisocial personalities lack empathy because they simply don't or can't register

others' feelings. Research has also suggested an overly reactive dopamine reward system,

suggesting that the drive to act on an impulse to gain stimulation or short-term rewards

regardless of the consequences may be more intense than the average person's.

As we mentioned before, because personality disorders are pretty much egosyntonic by definition,

people don't often acknowledge that they have a problem or a need for treatment - and in

the case of Antisocial Personality Disorder, even if they did, there aren't many specific

treatments available, at least not for adults.

But there are some promising interventions for kids and adolescents whose minds and brains

are more plastic and adaptable. In this way, the best way to treat Antisocial Personality

Disorder may be in trying to prevent it. According to American psychiatrist Donald W. Black,

among others, many kids diagnosed with Conduct Disorder, the diagnostic precursor to Antisocial

Disorder, are at high-risk for developing Antisocial Personalities as adults. But by

identifying warning signs early on and by working with these kids and families to correct

their behavior and remove negative influences, some of that impulse fearlessness could be

channeled into healthier directions, like to reward promoting athleticism, or a spirit

of adventure. It's important to remember that Antisocial Personality Disorder is only one

type of personality disorder. This is a diverse family of psychological conditions determined

by many different factors and we're still in the early stages of diagnosing and understanding

the mechanisms behind them.

Today, you learned about personality disorders and the difference between ego-dystonic and

ego-syntonic disorders. We looked at the three clusters of personality disorder, according

to the DSM V, and how personality disorder symptoms often overlap. We also took a look

at Borderline and Antisocial Personality Disorders, including their potential bio-psycho-social roots.

Thank you for watching, especially to all of our Subbable subscribers, without whom

we could not make Crash Course. To find out how you can become a supporter, just go to

Subbable.com/CrashCourse.

This episode was written by Kathleen Yale, edited by Blake de Pastino, and our consultant

is Dr. Ranjit Bhagwat. Our director and editor is Nicholas Jenkins, the script supervisor

and sound designer is Michael Aranda, and the graphics team is Thought Cafe.