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Before I discuss the female psychopath, I will first address how to diagnose a psychopath—a subject of ongoing confusion. Once the distinction is clear, we can explore examples of how female psychopaths are similar to, and different from, their male counterparts.

Two different terms, a similar problem

The diagnosis "psychopath" is best made with the Psychopathy Checklist–Revised (PCL-R, 2003) developed by Robert Hare. The PCL–R consists of 20 items, which are scored from 0 to 2 depending on how well each item fits an individual. The maximum score is 40, which is extremely rare. Within research, 30 is the accepted threshold for psychopathy (Hare, Hart and Harper, 1991).

Psychopathy is not the same thing as Disorder (APD), the disorder which refers to a lack of and also often seen with psychopathy. The APD diagnostic structure is included in the , now currently in its fifth edition (American Association, 2013). Note: Because the DSM-5 is so new, the research referred to in this article refers to the fourth edition of the manual.

The difference between psychopathy and APD is made more confusing by the fact that the DSM includes the APD diagnosis but not the distinct diagnosis for the psychopath.

Research supports that Antisocial (APD) and psychopathy are two distinct entities, despite overlapping in some ways. According to Widiger et al. (1996), a majority of men in prison (70-100%) qualify as presenting APD whereas the Psychopathy Checklist–Revised only diagnosed 28% of men in prison a Canadian study, and 25% of men in a Swedish prison study (Stalenheim & Knorring, 1996).

According to Hart and Hare (1996), all individuals who have been diagnosed with psychopathy will also have APD but not all individuals suffering from APD will be diagnosed with psychopathy.

In short, the diagnosis reflects a more severe disorder than APD.

Research on the female psychopath

For years, the research has told us that psychopaths are usually male. Research on psychopaths largely stems from studies conducted from prison samples, but remember that those in prison are there because they have been caught. We will never truly know the exact prevalence of male or female psychopaths because many only come to light once they have been arrested for a . (Hare estimates that approximately 1% of the population are psychopaths.) Is it possible that women can get away with certain crimes more than men because society is less likely to expect certain antisocial or violent behaviors among them? It certainly is.

Warren et al. (2003) found female occurrence rates of psychopathy of approximately 17% in prison populations—significantly lower than the rates for men in prison (Winn et. al, 2012). I regularly attend trainings and hear experts talk about how the number of female psychopaths is much higher than currently reported. Until we have research to inform us, however, it does not make sense to entirely contradict years of research which says that more men are psychopaths than women.

How are female psychopaths different from male psychopaths?

Robert Hare, the developer of the Hare Psychopathy Checklist, offers the following analysis: "The variety and severity of criminal acts performed by these women, as well as their capacity for cold-blooded violence, are similar to those committed by their male counterparts."

Research suggests that young women who later become psychopaths may look different than young men who later present the same disorder. Specifically, Verona (2006) found that young women who later develop the disorder show a more relational form of characterized by , , manipulation, and verbal aggression.

Other research has examined the importance of relational aggression among females, suggesting that women may display aggression differently than their male counterparts. Crick and Grotpeter (1996) studied relational aggression, also known as covert aggression, which is a type of aggression in which harm is caused by damaging someone's relationships or social status—and it’s different from the type of aggression (typically, physical) that males show each other. Relational aggression tends to be more subtle and manipulative.

It may be that while many male psychopaths act in traditionally aggressive, socially-constructed ways which can eventually lead them to be incarcerated (and evaluated for psychopathy), female psychopaths operate in more nuanced, less overtly physically aggressive ways, though they can ultimately lead to equally destructive outcomes. Think of a seemingly kind older female nurse who cares for a sick man. This woman could well be a psychopath but her presentation as an older woman in a helping profession causes others to see her in a benevolent light.

Does size and strength factor into the development or practice of psychopathy in men and women? On a common sense level, size and strength do matter. Perhaps a female psychopath must rely more heavily on manipulation than physical intimidation, or on teaming up with a male psychopath to achieve her .

An example of a female psychopath

As a psychologist who conducts violence threat assessments, I see firsthand how females can show the same capacity for psychopathy that I have seen in males. The hallmarks—eerie detachment from emotion, lack of conscience or remorse, glibness, and comfort and pride in breaking with laws and social conventions.

I recently evaluated a 27-year-old female who met nearly every criterion for psychopathy. She sat on the couch in my office and recounted how she mutilated and killed her pet bunny with a pencil, how she took a video of the entire act, and how she hasn't regretted her actions for a moment. She epitomized cool and calm as she explained, "I looked at him and knew his days were over." This young woman is a psychopath, just one of many that may go unnoticed at work, the gym, or the supermarket.

The psychopath I describe above is different from the vast majority of women, but not from other female psychopaths. Psychopaths often start practicing their kills with animals, as my female client exemplified. For my client, the bunny wasn't the first animal she had tortured; she had practiced torturing a couple of smaller animals before, starting as a teenager.

Female psychopaths, like their male counterparts, often practice with animals but ultimately move on to higher-stakes targets—humans. The good news is that since animal cruelty is against the law, psychopaths sometimes get arrested for those acts, which introduces them to legal repercussions, perhaps slowing them down or causing them to try to control their impulses to hurt people.

Are mothers who kill their children psychopaths?

One area of inquiry that requires more research is whether women who kill their children are actually psychopaths. Think of any number of the highly publicized trials of women charged with killing their children. Are they psychopaths?

The truth is that mothers kill their children for a variety of reasons—command auditory tell them to do it; they suffer from other mental illnesses which preclude them from managing the complex demands of ; or they either never wanted to have children in the first place or coolly decide after the fact that they don't want their children and must get rid of them. Because there is so little research available on the topic, I can only hypothesize that some—but not all—of the subset of women who kill their children are psychopaths.

Are female school shooters psychopaths?

In conducting violence threat assessments in schools, I work hard to understand the psychological motivations of school shooters so that I can prevent an at-risk kid from turning a violent into a reality. Are male school shooters psychopaths? Are female school shooters psychopaths?

We need more research to inform us about how these individuals would score on the PCL–R, for example, but many shooters ultimately kill themselves so no one gets the chance to test them. My anecdotal experience is that many school shooters—male and female—are full-blown psychopaths or, at least, have many psychopathic characteristics.

Final analysis

The female psychopaths I have assessed are every bit as dangerous as their male peers. The important point is for society—and clinicians—to understand that the female psychopath may look different on the surface because the behaviors are different.

Underneath her exterior, though, the female psychopath operates from the same conscience-free, bent-on-manipulation-and-winning mindset. If a woman is a psychopath, she can be just as dangerous as a male psychopath—perhaps more so because, based on social conventions, we're less likely to see her coming.

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