Lillyth Quillan knew almost immediately that something was wrong with her baby. At around eight months old with eight sharp new teeth, he began deliberately biting her breast as she fed him, then looking her in the eyes and laughing. Even though she cried out and pulled him away for significant stretches of time, whenever she returned to nursing, he’d bite again—and then snicker. Within days she had to switch to bottle feeding.
Quillan’s son, Alex (his name has been changed for privacy), was almost expelled from preschool because he repeatedly hurt other children. In middle school he began stealing and selling his parents’ electronics. He would pretend to hug his mom, then headbutt her instead. “I remember hitting my mom as a kid,” Alex says. “I know I shouldn’t have enjoyed it, but at the time, I did.” He adds, “If you’re looking for a reason, I wish I had it.” By high school he was using a gun to commit armed robberies.
Quillan, who comes from an upper-middle-cl*** family of northern California artists, was 22 years old and essentially a single mother when she started raising Alex. By the time he was five, she’d married her now husband, who adopted Alex. The couple tried all types of discipline short of corporal punishment. They saw counselors, psychologists and psychiatrists; wasted thousands of dollars on brain scans; got diagnoses of attention deficit hyperactivity disorder and Asperger’s syndrome; and tried medications, therapies and special education. Nothing worked.
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Finally, when Alex was 14, Quillan told her own therapist that she thought her son was a sociopath. The therapist said such terms weren’t used to describe children—but she diagnosed him with conduct disorder, which can be a precursor to psychopathy in adults.
Conduct disorder is characterized by defiance of rules, aggression toward people or animals, and ongoing cruelty such as bullying. It affects between 2 and 5 percent of children between the ages of 5 and 12 and up to 9 percent of teenagers. The type that Alex turned out to have comes with so-called callous-unemotional (CU) traits and is seen in up to 2 percent of children. CU traits—a lack of empathy and generally low emotional response—can be caused or exacerbated by child abuse or neglect, but genetic predispositions alone can also spur their development. When they appear as early as they did in Alex’s case, they are overwhelmingly driven by genetics and more likely to develop into adult psychopathy. (At least one relative on each side of Alex’s biological family seems to have some of these traits.)
Psychopathy sits at the uncomfortable intersection of mental illness and morality, with symptoms such as cruel behavior and remorselessness that inherently raise questions about the line between medicine and criminal law. Consequently, research in the area is underfunded and relatively sparse—despite the fact that the costs of failing to address the condition, which drives many of the most heinous violent or financial crimes, are billions of dollars annually. Parents like Quillan, who founded the first Facebook support group for people with children like Alex, are caught in the crossfire.
Treating adult psychopathy is extremely difficult, but there is hope for children with CU traits. Long-term studies have found that around half of them do not progress to psychopathy and instead go on to lead relatively normal lives, typically because of nurturing caregivers or other protective factors in their environment. At 25, Alex has been steadily employed for four years, and he has a good relationship with his parents. “He feels terrible for what he did,” Quillan says, noting that he has repeatedly apologized to her.
Because the positive influences that can help children grow out of CU traits are not always present, experts agree that it is best to start treating kids well before harmful tendencies become ingrained. “Early intervention is something we really ought to be investing in,” says Essi Viding, a professor of developmental psychopathology at University College London.
Television serials may dwell on the sadistic criminal, but research suggests executives and politicians also have high rates of psychopathic traits.
Many thorny issues complicate such treatment, however. One is that children with CU traits don’t respond to punishment, which is often what parents, teachers and society at large rely on to deter harmful behaviors. Successfully treating these children—reducing their callousness and unemotionality or at least redirecting their attention toward constructive endeavors—requires creative methodologies that are informed by the emerging neuroscience of psychopathy.
First cl***ified by psychiatrist Hervey Cleckley in 1941, psychopathy has long confounded physicians, police and the public. The condition is full of contradictions. People with psychopathy can carry out cold, calculated crimes and cons that require significant planning, but they may also engage in wildly impulsive aggressive behavior. They can understand the perspectives of other people well enough to manipulate their emotions but lack the intuitive emotional empathy that would help them care about causing harm. Most disturbing, unlike people with cl***ic psychiatric illnesses such as schizophrenia, people with CU traits appear socially typical and may even be charismatic. Television serials tend to dwell on the sadistic criminal, but some research suggests executives and politicians have high rates of psychopathic traits as well.
Like other personality disorders, psychopathy exists on a spectrum from mild to severe. The severe form is believed to affect around 1 percent of the general population and is far more common in men than in women. According to a study published in 2021, among people imprisoned in the U.S., up to one quarter of men and up to 17 percent of women meet the criteria for psychopathy. The condition is typically diagnosed based on a measure developed by psychologist Robert D. Hare in the 1970s and since modified to improve precision. Because psychopathy is marked by dishonesty, Hare’s checklist is scored not only according to an individual’s responses on a questionnaire but also with input from clinicians, family and others who have knowledge of relevant behavior.
One widely accepted view, the triarchic model, first proposed in 2009 by psychologist Christopher Patrick of Florida State University and his colleagues, divides psychopathic traits into three domains: boldness, meanness and disinhibition. To meet the criteria for psychopathy, people must have some of each. Disinhibition—saying or doing whatever you feel without considering consequences—and poor impulse control are common in other psychiatric conditions (such as bipolar disorder), but the combination of fearlessness, callousness and remorselessness is unique to psychopathy.
Curiously, psychopathy is not included in the Diagnostic and Statistical Manual of Mental Disorders, the most recent edition of which is the DSM-5. Disagreements about the nature of psychopathy, as well as concerns that too many people would receive a highly stigmatizing label, prevented its inclusion in the DSM-IV more than 30 years ago.
The DSM-5 does, however, include antisocial personality disorder (ASPD). Nearly all people with psychopathy will qualify for ASPD diagnoses as well, but the converse is not necessarily true: ASPD is a much broader category. People with ASPD might mug grandmothers to get drugs, for example—but many of them will feel guilty afterward, and they may stop their harmful behavior if they gain better impulse control. In contrast, people with psychopathy might not care about or might even enjoy knocking helpless people down. Adding to the confusion is sociopathy, an antisocial behavior disorder that was once believed to be caused by social factors such as child abuse. The term is often used interchangeably with “psychopathy” but has no widely accepted definition.
The DSM-5 also includes childhood conduct disorder, the diagnosis that Alex finally received. It is a prerequisite for an ASPD diagnosis and a predictor of adult psychopathy. If school-age Alex were diagnosed today, he would almost certainly qualify for the newly added DSM-5 specifier “with limited prosocial emotions,” which captures the coldness and remorselessness that characterize adult psychopathy.
Callous and unemotional traits are ***ociated with alterations in the brain that impair the individual’s ability to experience sensations and emotions—especially negative ones—in themselves and in others. To begin with, people with these characteristics have a reduced ability to feel pain. Quillan describes an incident in which Alex fell and needed to have the resulting wounds on his head stapled. At the emergency room, their doctor panicked after realizing she had forgotten to use any local anesthetic before she began stapling, but Alex said it didn’t hurt and told her to continue.
In 2012 Jean Decety and his colleagues at the University of Chicago first showed that teens with CU traits have higher thresholds for their own pain and abnormal brain responses to images of other people in pain. The study, which was conducted in Taiwan, compared the responses of 13 young offenders with CU traits with those of 15 incarcerated youths who did not have these traits and 15 typical control participants of the same age. In one part of the experiment, participants placed their hands in a device that applied gradually increasing pressure and reported when it started to hurt. Compared with both control groups, it took significantly longer for the CU youths to report pain.
The researchers also measured brain-wave responses using electroencephalography (EEG) as these teens viewed pictures of others in painful situations. Those with high levels of CU traits perceived others as having less pain than the other participants estimated. Correspondingly, the EEG measurements from this group showed less responsiveness in brain areas involved in perceiving pain. Similar results have been reported in other research on CU youths and adults with psychopathy. For example, a 2025 study found reduced levels of sensitivity to their own pain in people with more severe psychopathic traits—which correlated with their lower levels of empathy for others’ pain.
Alex says that when he was a child, he sometimes saw hitting his mother as being “playful.” But, he adds, “if she said ‘ow,’ I didn’t think it was an actual ‘ow.’ You know, like, if you flick my hand, I’m going to say ‘ow,’ but obviously it doesn’t hurt.” He literally did not perceive her pain.
By itself, however, reduced pain perception doesn’t imply psychopathy. People born with genetic conditions that cause complete pain insensitivity have varying empathy levels, just as people in general do. Although they respond less empathically to pictures of people’s limbs in painful situations, such as having a car door slammed on their hand, their response to facial expressions of pain is normal. Their empathy level, not their condition, predicts their concern for someone who might be hurt.
But people with CU traits also have difficulty recognizing facial expressions of distress. Researchers who have studied such people’s brains have found changes in the insula, which helps with intuitive perception of the emotional state of oneself and others, as well as reduced volume in the orbitofrontal cortex, which is involved in understanding one’s own and others’ perspectives. These changes imply difficulties in both experiencing intuitive empathy and feeling concern for others’ viewpoints.
Those with callous and unemotional traits easily make friends and—at least initially—seem charming.
Before Alex was properly diagnosed, he was mislabeled as autistic and placed in autism-focused special education. In fourth grade, his cl*** was given daily worksheets aimed at helping the students identify emotions in facial expressions, an ability that is sometimes impaired in people with autism. “My son had a 100 percent failure rate on negative emotions” such as fear, Quillan says.
A 2012 review of research, published by Amy Dawel of the Australian National University and her colleagues, shows that CU traits can also be ***ociated with deficits in recognizing positive emotions such as happiness. Still, the link is strongest for fear and sadness. This disability seems likely to increase harmful behavior simply because if you don’t know when you are hurting or terrifying people, you are less able to avoid it.
Attention and focus are also aberrant in people with psychopathy. Once CU children or psychopaths zero in on something they want to obtain or achieve, they tend to have an extremely restricted view of the world—so much so that they lose awareness of the potential for harm to themselves or others. “It’s like this ultrafocused attention on reaching a goal,” says neuropsychologist Inti Brazil of Radboud University in the Netherlands. Viding, the developmental psychopathologist at University College London, for example, recalls working with a child who ritually killed ducks. She describes it as a kind of habit for the child, resembling the type of obsessive interest and rigidly patterned behavior seen in some autistic children.
Autism is also linked with difficulties with empathy. But research now indicates that autism and psychopathy are, in many ways, opposites. For one thing, when autistic children struggle with empathy, the problem is most frequently that they are overwhelmed by other people’s distress, not unconcerned about it. “I think the reason people used to think those on the autism spectrum can’t empathize is that they often would do things that would look cold and callous,” Viding says, describing how an autistic child might abandon someone who is crying. This choice can come across as “unfeeling,” she says, but “you walk away if you feel distressed by the cries and don’t have the social skills to engage.”
Another contrast: Autistic people often care deeply and yearn for connection, but they have trouble making and keeping friends. Those with CU traits, however, easily make friends and—at least initially—seem charming. They tend, however, to see relationships as ways to exert power or get other things they want, not as reciprocal connections. Another opposing characteristic is that autistic kids tend to prefer to follow rules and are often obsessed with justice and repelled by hypocrisy, whereas CU children deliberately violate laws and conventions. “We have shown with genetically informed twin-study research that the genetic risk is almost entirely separate,” Viding says.
Another contradistinction between these conditions is that autistic people tend to be very anxious, whereas those with CU traits often appear unflappable. Studies have found alterations in emotion-related brain regions such the amygdala—which processes strong emotions, including fear—in people with psychopathy. A 2015 study by Leah M. Lozier, then at Georgetown University, and her co-workers found that the less a CU child’s amygdala responded to fearful faces, the more likely that child was to act aggressively without provocation. For his part, Alex still tends to find danger exciting rather than frightening. As a child, he loved risky activities such as BMX riding and skateboarding, and now he rides a motorcycle. “I was always an adrenaline seeker,” he says.
Psychopathic traits do have some upsides. They seem to confer resilience to stress and an ability to act calmly under duress. CU children tend to have a low resting heart rate, which is also ***ociated with stress resilience. A higher resting heart rate correlates with anxiety and stress sensitivity. Research published in 2021 by David Farrington of the University of Cambridge and his colleagues showed that children whose hearts beat faster than average at age eight were at lower risk of developing adult psychopathy, despite having adverse childhood experiences such as harsh discipline and an incarcerated or depressed parent.
Nick Thomson, an ***ociate professor of psychiatry at Virginia Commonwealth University, notes one potential explanation for why studies of CU children and fear show varied results. Typically when people are frightened, the (inaptly named) sympathetic nervous system goes into overdrive, causing anxiety, raising heart rate and blood pressure, and reducing focus on anything other than responding immediately. Only after the danger has p***ed does the countervailing parasympathetic system, which is calming and better suited to long-term planning, kick in.
In CU children, however, these systems are activated simultaneously in scary situations. “Kids with callous-unemotional traits do respond to fear, but they’re responding in a way that could be perceived as fearless,” Thomson says. “They’re engaging both branches of the autonomic nervous system, so they’re getting the benefits of both. They’re staying calm and relaxed from the parasympathetic, but they’re alert and attentive from the sympathetic. It’s probably one of the most ideal kinds of responses”—and it may allow people to succeed in occupations such as firefighting or policing that require poise under extreme stress.
Perhaps the most confounding characteristic of people with callous-unemotional traits is that punishment does not deter them from doing harm. This attribute has been remarked on since Cleckley first described psychopathy. Criminals diagnosed with psychopathy often commit repeated offenses after being released from prison, for instance. People with CU traits may be unable to learn from punishment, partly because they have little fear; additionally, they may have deviations from the norm in their striatum, a part of the brain that helps people predict and encode reward and punishment. Treating children who have CU traits therefore requires methods that are tailored to their specific characteristics—which require an accurate diagnosis.
Unfortunately, clinicians often avoid diagnosing conduct disorder because of labeling fears, a phenomenon that Quillan encountered several times. Such fears are understandable: labeling children with stigmatizing conditions can harm them if that label makes the adults around them more punitive and less supportive of their ambitions. But parents like Quillan, as well as some experts, argue that in cases like Alex’s, the lack of an accurate label does even more damage, leaving families to struggle without help—or with inappropriate therapies and the criminal prosecution system. “I’m pro-label because we need to know what we’re dealing with,” Quillan says.
“The parents who come to me are never asking, ‘How do I help my kid with this stigmatizing label?’” agrees Abigail Marsh, a professor of psychology at Georgetown. “What people actually want is help. So I think the correct diagnosis is the only route to get the correct treatment.”
Another issue is that group treatments in residential facilities, where many CU youths wind up by their teens, can be counterproductive. These centers tend to aggregate kids with disparate psychiatric disorders and trauma histories. Teens in general are strongly influenced by their peers. When you place adolescents with CU traits together, it can normalize antisocial behavior rather than deterring it, a process described by the late psychologist Tom Dishion of the University of Oregon as “deviancy training.”
After multiple arrests and stints in juvenile hall, at age 16 Alex was sent by a judge to a California residential treatment facility. The program itself didn’t offer much; Alex was still on a waiting list to see a psychiatrist when he left after nearly two years. There was no therapy beyond a basic points system that rewarded good behavior and punished violations and was apparently easy to game.
It is extraordinarily difficult to lovingly parent a child who doesn’t care about harming you or even enjoys it.
The lack of programming beyond high school cl***es left plenty of room for deviancy training. One of Alex’s cl***mates, for instance, had grievously wounded his mother by planting a bomb designed to produce maximum shrapnel in the family’s oven. He offered to teach Alex how to make a similar one—but, fortunately, Alex wasn’t interested in the technical details.
One experience did seem to have a positive impact, however. While waiting to use the phone, Alex overheard another teen—whom he described as a hardened gang member—speaking with his mother. From what he could hear, Alex deduced that not only had the mom forgotten her child’s birthday, but she didn’t even know his age. The young man, who was one of the toughest kids in the center, broke down in tears.
When it was his turn to use the phone, Alex called his mother and began genuinely apologizing to her for the first time. He’d thought his parents were being deliberately hateful and mean to him. Their relationship had become one of constant conflict. Because the legal system has recognized that tough sentencing for young people is often counterproductive, Alex had frequently been able to evade those kinds of consequences. But his parents consistently—and, it seemed to him, relentlessly—disciplined him. He began to realize that they did it because they cared.
“My son actually called me, and he was like, ‘Mom, I am so sorry,’” Quillan says. He told her that he knew she’d never forget his age or his birthday and that he felt bad for misinterpreting her attempts at discipline as a lack of love. “I think it was seeing someone who had it worse,” Alex says. “Seeing the polar opposite of what I went through put it into perspective.”
Counterintuitively, the fact that Alex’s condition is “primary,” or thought to be largely genetic in origin, probably means it was easier for him to recover than it would have been otherwise. It might seem like “secondary” CU traits, which develop in response to childhood maltreatment or personally traumatic events, should be more readily altered, but in fact kids with primary callous-unemotional traits seem to be more pliable. For CU children, at least, nurture trumps nature.
“We’ve developed a treatment for kids with callous and unemotional traits, with the idea of preventing psychopathy,” says Eva Kimonis, a professor of psychology at the University of New South Wales in Australia, who conducted the first study that compared treatment outcomes for people with primary versus secondary CU traits. “Both groups improved,” she says, “but this primary group maintained its gains, whereas the secondary group deteriorated.”
The study included 45 families with children between three and seven years old who had serious CU traits and conduct disorder. The researchers used a technique called parent-child interaction therapy, which they adapted to address callous behavior. In 21 weekly hour-long sessions, which the families participated in one at a time, each parent and child interacted in a special playroom with a therapist observing from behind a one-way mirror. The parent, usually the mother, was fitted with a headset so the therapist could direct their play.
The first goal was to break patterns like the one that had developed between Alex and Quillan by his teen years, in which he had come to believe that she hated him. Because CU children don’t change their behavior when punished, effective treatments aim to restore warm, rewarding relationships. Experts emphasize that consistent consequences must be imposed when harmful behavior occurs to avoid unfairness to others. Still, the focus in treatment is on rewarding good actions, which—unlike punishment—does drive change for these children.
Early sessions focus on helping the parent and child reengage warmly and letting the child lead imaginative play with toys. Research has shown that CU children with warm parents who set appropriate limits are more likely to outgrow these traits. But it is extraordinarily difficult to lovingly parent a child who doesn’t care about harming you or even enjoys it. The therapy aims to bolster parents’ skills and avoid a cycle of swinging between harsh discipline and avoidance. Trained therapists help parents learn to praise even small improvements and to be emotionally expressive and demonstrative.
In later sessions the emphasis is more on discipline, which can include consistent time-outs when needed. But the therapists teach the parents to use rewards as much as possible and help them tailor the types of rewards provided to appeal to the individual child’s interests. Guided by the therapists, parents teach their children to recognize distress in faces and voices. Parents are also encouraged to provide special rewards and be especially attentive to comp***ionate and loving acts by their children. When the child is angry or aggressive, parents and therapists identify the triggers and teach more constructive coping responses.
“We try to figure out what these kids are motivated by,” Kimonis says. “How can we reward them for the good behaviors that we want them to be doing, like listening to their parents and behaving in gentle and nonaggressive ways?”
Improvements achieved through the therapy were striking: 58 percent of the children with primary traits whose families completed treatment (the majority of those who started it) no longer met clinical criteria for CU traits three months after the study ended. “They came in perhaps listening to the parent 20 percent of the time, and now they’re going to 80 percent of the time,” Kimonis says, noting that the reduction in destructive behavior improves the parent-child relationship. That, in turn, makes it warmer and helps end one cycle that worsens CU traits.
Another promising approach, being developed by Thomson, uses a virtual-reality environment to train emotion recognition and regulation in a gamelike, fun experience. The researchers tailor treatment to individuals so that the programming is challenging enough to maintain interest but not so challenging as to be frustrating. “They’re immersed in the story,” Thomson says. “They don’t have the distractions of their phones and everything else. They’re inside it, and it’s very reward-focused.” The storylines involve social experiences such as parties, along with games that help to improve relevant skills.
Thomson says 98 percent of the CU children age 10 to 17 who have tried it liked it—which is critical because many of them resist talk therapies. In pilot research, it improved recognition of all emotions but particularly sadness and fear, for which CU kids have the greatest deficits. The authors of a forthcoming paper found that these changes were accompanied by reductions in aggressive behavior and rule violations—as well as in the severity of CU traits themselves. If backed by further data, this approach could be particularly useful because it does not aggregate these children in groups, it is less resource-intensive than other family interventions such as parent-child interaction therapy, and it could be used pretty much anywhere.
When Alex left the residential treatment center at age 18, he had more insight into his behavior but, unsurprisingly, did not turn around overnight. Both mother and son say that what made the real difference was the fact that he found a mentor in a boss who hired him to work at his auto-related business. The man was highly respected in his community and church—and Alex saw that he could be like him only if he, too, behaved honorably.
“I think it just was ‘right people, right time,’” Alex says of the experience, describing the joy he felt when he was praised for good, hard work. “It was feeling that it was actually genuine and not just a compliment because they’re trying to get something from you,” he says. And this understanding meant that when he did get something wrong, “I would own up to it instantly because I cared about them, too, so I wouldn’t want to lie to them.”
Being more mature probably helped on its own—research shows that the prefrontal cortex, which checks impulsive behavior, typically does not finish developing until the person is in their early to mid-20s. This delay may be why all types of criminal and antisocial behavior show peaks in the late adolescent and early adult years.
Alex still has the intensity of focus that led him to be careless when pursuing misguided goals in the past. He knows he has to make sure he continues to guide it in the right direction. But, sometimes to his annoyance, these days he feels more. As a child, he’d often laugh at films that terrified his peers. Now, he says, “the stupidest movie will make me cry. It’s quite irritating, I’ll be honest.” Overall his intentions have changed for the better, and he’d like to use his calmness under pressure to serve in the military or law enforcement. “I think it was just me pointing my arrow at something else,” he says.
