A new meta-analysis has shed light on the complex links between hormonal activity and psychopathic tendencies, raising the prospect of more nuanced approaches to identifying and supporting at-risk youth. The study, published in Psychology & Neuroscience, draws on 25 years of worldwide research and upends some previous assumptions about the biology of personality disorders, with potential implications for prevention and mental health services in Thailand and beyond (psypost.org).
At its core, the research reviewed studies examining the role of endocrine system hormones—such as cortisol, testosterone, estradiol, oxytocin, and dehydroepiandrosterone (DHEA)—in the development of psychopathic traits, especially during the sensitive years of adolescence and early adulthood. The strongest and most consistent finding was a statistically significant association between higher baseline levels of cortisol—the body’s primary stress hormone—and the impulsive, antisocial dimension of psychopathy.
The significance of these findings is striking for Thai readers, given the nation’s increasing concern over youth behavioral problems and the importance of early intervention in mental health. Psychopathy is characterized by two major clusters: one involving emotional detachment (callousness, shallow affect, lack of empathy) and another tied to behavioral impulsivity and antisocial actions. In Thailand—like in many countries—addressing juvenile crime, school discipline, and youth rehabilitation integrates insights from psychology, education, and social work. New biological findings such as these open the door to more holistic and evidence-based responses.
The reviewed studies—26 in total, conducted between 1998 and 2023—explored a variety of hormonal influences. Cortisol is best known for its role in the fight-or-flight response. Surprisingly, instead of confirming the “Low-Fear Hypothesis” (which suggests people with psychopathic traits would have chronically low stress responses), the new meta-analysis revealed that higher resting cortisol levels were most commonly associated with the impulsive and antisocial aspects of psychopathy, not emotional detachment. This challenges decades of assumptions and suggests a more dynamic interplay between behavior and biology than previously thought.
Findings related to other hormones were less consistent but nevertheless intriguing. Several studies linked higher testosterone levels—known to drive aggression and risk-taking in both men and women—to increased impulsivity, aggression, and lower sensitivity to rules and punishment among those with psychopathic features. The hormone DHEA, also related to stress responses, sometimes tracked with more severe psychopathic tendencies in adolescents. Meanwhile, decreased levels of oxytocin—the “bonding hormone” central to empathy—were occasionally observed in individuals displaying high levels of emotional coldness, though this was not a universal finding.
Senior researchers in Portugal, who led the systematic review, were quick to note several limitations. The variability of evidence may reflect differences in study design, sample population (from forensic settings to community samples), methods of measuring psychopathy (questionnaire vs structured interview), and timing or technique of hormone assessment—a crucial consideration in studies involving complex human behaviors. Only seven out of the 26 studies were robust enough to be included in the quantitative meta-analysis, limiting the scope for subgroup analysis by sex, age, or other potentially significant modifiers.
Expert commentary on these results highlights both the promise and the constraints of current science. “What’s exciting is that we’re starting to find biological signatures that could one day contribute to screening tools or targeted interventions,” said one international adolescent psychiatrist, emphasizing the role of hormones in identifying neurodevelopmental risk. “But the evidence is not consistent enough yet for clinical decisions—more research in diverse populations, including young people in Southeast Asia, is vital.” (psypost.org)
For Thailand, these findings are particularly relevant as public health authorities, schools, and mental health professionals seek new strategies to address rising rates of juvenile delinquency, bullying, and violence. With adolescent mental health already prioritized in national policy and the Ministry of Public Health supporting school-based screening for behavioral problems, the integration of biological risk markers—if proven effective—could enable earlier, more personalized interventions, reducing the risk of progression to more serious conduct disorders or adult criminal behaviors.
Thailand has a unique sociocultural context: Buddhist values of compassion and community harmony have long underpinned both education and rehabilitation approaches. Traditionally, behavioral and personality issues have been seen through moral or social lenses, but as the nation modernizes, there is growing openness to integrating biological and psychological science into prevention and care. Yet, a key concern is ensuring that biological findings are not used to stigmatize or “label” young people but to offer more supportive and tailored assistance before problems escalate.
The historical context is important: previous generations of Thai youth experienced discipline and conformity through family, religious, and school structures, but today’s adolescents face new pressures related to urbanization, technology, and changing family dynamics. Mental health advocates warn that the stressors associated with social media, academic performance, and economic insecurity may exacerbate underlying biological susceptibilities, making early identification and intervention more critical than ever (Bangkok Post). Meanwhile, concerns about substance use and violence among teens have prompted both government crackdowns and calls for more compassionate, evidence-based prevention strategies (World Health Organization: Thailand Mental Health Profile).
Looking ahead, the international research team highlighted future directions for research, calling for more comprehensive studies into stress hormones such as adrenaline and noradrenaline, which were largely omitted due to data limitations. There is also a need to untangle how age, puberty, co-occurring disorders (such as conduct disorder or ADHD), and gender interact with hormonal underpinnings of psychopathic traits. Integrated models that combine hormonal measurement with psychological assessments, educational performance, and family background are likely to yield the most useful insights for practitioners and families alike.
For Thai readers, practical recommendations from this new body of work include:
- Advocating for cross-disciplinary approaches in schools, combining teachers, counselors, and healthcare staff to screen for and address early signs of severe behavioral issues.
- Supporting education campaigns that increase awareness of both environmental and biological risk factors among parents, teachers, and community leaders, while avoiding stigma and reinforcing the importance of early and empathetic support.
- Encouraging more local research into hormonal and psychological markers among Thai youth to identify cultural nuances and preventive opportunities relevant to Thai society.
- Maintaining mindfulness in policy: while biology provides powerful new clues, holistic care—including family involvement, emotional support, and community resources—remains essential in supporting youth who may be at risk.
As research continues, Thai policymakers and educators should remain attuned to these emerging scientific insights while upholding the country’s core values of inclusion, compassion, and respect. Early detection and support, grounded in both biological science and Thailand’s unique social fabric, could help a new generation navigate the challenges of modern life more successfully and safely.
For those interested in learning more, the full research summary is available via psypost.org, and up-to-date resources on adolescent mental health can be found through the Thai Ministry of Public Health and the World Health Organization (WHO Thailand).