Rasmus Rosenberg Larsen

In a nutshell

Psychopathy Unmasked is a book about “psychopaths.” But it’s not your ordinary run-of-the-mill account that repeats the well-worn story of violent people naturally disposed to wreak havoc in our society.

Instead, Psychopathy Unmasked is both investigative scientific criticism and criminal justice activism. More uniquely, it’s actually the first book ever to take a sustained critical look at the science of psychopathy and how the legal system has used—and, I argue, misused—the diagnosis.

To give you a cohesive sense of my book, I should first sketch some background information:

Most people have some sense of what terms “psychopath” or “psychopathy” means. When I use these terms, perhaps you picture a serial offender who has no empathy or sense of social responsibility; someone who cares only for themselves. This image has been popularized in films like Anton Chigurh in No Country for Old Men or Hannibal Lecter in The Silence of the Lambs. I’m sure you have your own favorite example. My students love to watch Dexter, a story about a psychopath who uses his callous personality to do good by killing bad guys.

While many of these fictional depictions are caricatures of psychopathy, they are not completely far from how the term is used in clinical and legal settings. In practice, psychopathy—or Psychopathic Personality Disorder as it is also called—is a diagnostic label applied to individuals with certain callous and unemotional traits and antisocial tendencies. For those who are interested in clinical formalities, psychopathy is commonly seen as a severe subtype of Antisocial Personality Disorder.

These are the formalities, but here is where it becomes both really interesting and ethically complicated. In the 1990s, and presumably as part of the “get tough on crime” movement, our criminal justice system slowly began to systematically screen justice-involved individuals for psychopathy. It started with a couple of hundred screenings each year, where today the practice has ballooned to tens or maybe hundreds of thousands yearly assessments in the U.S. and Canada.

On top of this, the diagnosis also became highly influential in legal decisions, a status that it still enjoys today. Once someone is diagnosed with psychopathy, the consequences can be severe, such as increasing the likelihood of non-mitigated sentences, denial of parole, placement in high-security prisons, juvenile transfer, and the diagnosis remains one of the preferred avenues for prosecutors to argue in favor of capital sentencing over life without parole.

Well, ok, and so what, you might think. Isn’t this a good development?

Some people have indeed argued that it is a good thing, that we should expect our legal system to do this; to systematically figure out which offenders are the true psychopaths in our society. We are told that these individuals are the “worst of the worst.” So why not treat them accordingly with targeted intervention? If we restrict psychopaths’ ability to roam freely, the argument goes, society will become a safer place.

If you find this argument convincing and even reasonable, then I fully understand. I did so too when I first took interest in this topic back in 2012. But as I began to study it more carefully, I quickly discovered that things are a bit more complicated.  

What I discovered was that for decades, scientists have tested whether individuals diagnosed with psychopathy truly fit the “boogeyman” image that is part and parcel of the psychopathy diagnosis. The findings are striking: they don’t fit the image. People diagnosed with psychopathy are not meaningfully more violent than other offenders, nor do they reliably lack empathy or impulse control. Basically, all the common claims that are made about psychopaths have never been corroborated by empirical research.

Yet despite this, psychopathic persons are still being treated differently in the criminal justice system, as the diagnosis introduces serious bias into decision-making. In Psychopathy Unmasked, I lay out the case for why we must stop using this diagnosis to shape legal outcomes.

A close-up

The structure of the book is relatively straightforward. There is a total of eight chapters, where five of them examine one of five central claims about psychopathy by reviewing research published between 1980 and 2024. For example, Chapter 2 investigates whether individuals diagnosed with psychopathy are more dangerous than other non-psychopathic offenders. And Chapter 5 examines the claim that psychopathy is correlated with distinct brain abnormalities.

Across these five central chapters, the pattern is clear: the common claims about psychopathy either lack meaningful empirical support or have been outright falsified by the research.

The chapter I am most proud of, however, is the closing Chapter 8. Here, I step back and ask what I believe is perhaps the most interesting and pressing question, and a question that the field has yet to grapple with:

Why is there such a large gap between what is being said about psychopathy and what the science actually shows?

Such a situation is very unusual in science. Typically, ideas that fail empirical tests are eventually abandoned. With psychopathy, the opposite has happened; the diagnosis has become more entrenched, despite mounting disconfirming evidence. It’s truly puzzling.

The explanation I put forward in Psychopathy Unmasked is that psychopathy is what scientists colloquially refer to as a “zombie idea.” It is an idea that is intellectually appealing or infectious, but at the same time scientifically dead. Like a zombie, it continues to wander the halls of science, repeatedly animating new generations of innocent researchers to believe in the reality of it. And with this uncritical acceptance begins yet another cycle where new researchers carry out a trove of studies that still fail to confirm the reality of psychopathy.

Chapter 8 will presumably be seen as controversial by my peers because it raises the possibility that psychopathy is simply a bunk diagnosis; that no one actually fits the stereotypical image of the “psychopath.” It’s easy to say that a person seems to be lacking the ability to empathize; but that doesn’t automatically mean that they truly do lack that capacity.

So far, science has never documented a clear case of a psychopath, a person that truly fits all the common descriptors about the diagnosis. Perhaps these people exist; perhaps one day they will be clearly documented. But the lack of evidence after decades of research is striking and I think it’s time for scientists to stop speculating and instead draw conclusions from their work.

If a browsing reader opened this chapter, I think they would see the heart of the book: a willingness to confront the uncomfortable possibility that what we have long believed about psychopathy may be thoroughly misguided.

Lastly

Psychopathy Unmasked uncovers a surprising story about a scientific field shaped by bias, spin, and questionable methods. This flawed science laid the foundation for the legal use of psychopathy assessments, which in turn has fueled large-scale injustices that remain largely invisible to the public.

The book is, in a sense, investigative scientific criticism, motivated by a personal ideal: to rid our legal system of unsound science. Its main purpose is to show that there are compelling reasons to doubt psychopathy as a diagnosis and that few inferences—if any—can be drawn from it in clinical and legal practices.

Importantly, the book is not about pointing fingers. The mainstream account of psychopathy is a powerful story. Looking back, it is easy to see how it was destined for quick adoption in legal practices. For decades, psychopathy has been portrayed as a chronic, dangerous disorder marked by coldness, impulsivity, and a lack of empathy. Some psychologists estimate it affects only 1% of the population, yet it is responsible for a disproportionate share of serious crimes. A truly captivating narrative!

But this narrative needs a critical counterpoint, and Psychopathy Unmasked provides it. While the book surveys the history of the diagnosis, its main contribution is a thorough review of the scientific claims that have justified its legal authority—claims about dangerousness, untreatability, empathy deficits, and moral psychological impairment.

The reality is that none of these claims withstand sustained empirical testing. Over the past two decades, research has consistently shown that individuals diagnosed with psychopathy are not substantially more violent or distinct than other offenders. They are not the “social predators” or “morally colorblind” characters portrayed in culture.

Meanwhile, tens of thousands of psychopathy assessments occur each year, shaping life-altering decisions in courts and prisons. Each use of the diagnosis carries the risk of unjust bias. The only responsible course, I argue, is to retire psychopathy assessments from legal use.

If the book leaves one lasting impression, I hope it is this: that future scientists and practitioners will recognize the dangers of prematurely importing psychiatric diagnoses and constructs into the criminal justice system.