Leanne ten Brinke’s book, “Poisonous People,” published by Simon & Schuster, delves into the complexities of dark personality traits, opening with a case study that challenges conventional expectations. Rather than focusing on a convicted criminal, the narrative begins by examining William O. Douglas, a prominent US Supreme Court justice.
Douglas, a celebrated figure in mid-20th-century liberal thought, is presented by ten Brinke, a psychologist, as someone who would likely meet modern criteria for psychopathy. Although his actions never escalated to criminal offenses, his personal and professional life reportedly left a damaging legacy.
Understanding Psychopathy and Its Evolution
The formal diagnosis of psychopathy was discontinued in 1952, largely due to associated stigma. It was later replaced by more nuanced diagnoses such as antisocial personality disorder. However, the term “psychopathy” re-emerged in the 1980s within a criminal justice context. Criteria, like those found in the Psychopathy Checklist Revised, were developed to assess individuals convicted of serious crimes and to gauge their likelihood of reoffending or being rehabilitated. Ten Brinke notes that individuals identified as psychopaths through such assessments, while representing about 1 percent of the population, are estimated to be responsible for half of all serious crimes.
Ten Brinke, who heads the Truth and Trust Lab at the University of British Columbia, posits that lacking a clinical diagnosis of psychopathy does not preclude the presence of elevated dark personality traits. She suggests that a broader segment of the population, potentially 10 to 20 percent, may exhibit these traits to a degree that doesn’t meet clinical “psychopath” standards, yet is significant enough to warrant attention.
The Dark Tetrad and Its Societal Impact
“Poisonous People” explores the societal costs associated with these “aggressive, predatory individuals” and offers strategies for mitigating their influence. The book introduces the “dark tetrad,” a framework developed over the past two decades by personality researchers. This framework identifies the confluence of four distinct personality traits: psychopathy, characterized by an utter lack of empathy; Machiavellianism, involving calculated manipulation; narcissism; and sadism.
While popular culture often portrays psychopathy as a binary condition, ten Brinke explains that it operates more along a spectrum. Individuals exist at varying points on this spectrum, with their scores on each trait being independent of the others. She writes that the 10 to 20 percent of the population scoring high on traits associated with psychopathy possess a particular inclination toward undermining ethical standards and fostering an atmosphere of fear and distrust.
Environmental Influence and “Situational Psychopaths”
Despite the unsettling nature of these findings, ten Brinke cautions against complacency. She argues that environmental factors significantly influence these personality traits, making them “malleable.” Through detailed case studies, she illustrates how adverse environments, termed “cultures of rot,” can transform individuals within the 80 percent who do not score high on dark traits into “situational psychopaths.”
The author explains that even kind and empathetic individuals can be susceptible to the influence of dark personalities. Factors such as extreme fatigue, oppressive heat, or even the fervent dynamics of sports fandom can normalize the perception of verbal and physical abuse towards others as an acceptable, even enjoyable, activity.
Protecting Ourselves and Fostering Self-Reflection
The book provides practical advice for individuals seeking to protect themselves from “poisonous people.” Establishing clear boundaries is highlighted as a key strategy, given these individuals’ tendency to identify and exploit unwritten social rules. However, a significant portion of “Poisonous People” is dedicated to encouraging introspection.
Ten Brinke poses critical questions about personal moral resilience and our role in enabling malicious behavior. She suggests that society empowers these individuals, placing them in positions where they can exert disproportionate negative influence. The author questions why people elect leaders with these traits or hire them for business management roles.
Challenging the Myth of the Competent Psychopath
Ten Brinke challenges the popular notion that dark traits are indicative of effective leadership. Her research involving investment bankers revealed an unexpected inverse correlation between psychopathy and financial performance. Managers exhibiting more malicious and cunning behavior generated significantly lower returns than their average counterparts over a ten-year period. Conversely, cooperative managers achieved the best results.
“If you want to make less money as an investor,” she concludes, “you would do well to find the meanest, most cut-throat predator to manage your wealth.”
The Role of Deception and Critical Thinking
The perception of the ultra-competent psychopath in popular culture, ten Brinke suggests, is often fueled by the individuals themselves. Those with dark tetrad traits are prone to excessive lying, particularly self-aggrandizing fabrications. This behavior is not only rewarding due to what she terms “duping delight” but also serves their objectives.
In a professional setting, an employee might falsely claim to be an effective leader or top performer. Ten Brinke notes that these claims could be based on narcissistic delusions or outright falsehoods. The tendency for people to readily believe these assertions makes them complicit in the harm caused by these individuals.
To counter this, ten Brinke advocates for enhancing critical thinking skills, a trait associated with Machiavellianism. This ability to engage in critical analysis can help individuals discern when they are being misled. She acknowledges that detecting deception is not a simple task, stating, “If lying were so easy and straightforward to detect, there would be little point in doing it.”
Cultivating Moral Resilience and Combating Toxicity
However, ten Brinke asserts that awareness and attention can make a difference. She uses the analogy of “bad apples” spoiling a barrel, suggesting that the majority have a choice in preventing the spread of “rot.” She hints at the existence of personality types within the 80 percent who can not only halt but may also reverse negative trends. These individuals combine dark traits with qualities not typically associated with them, such as empathy and conscientiousness.
The existence of such individuals challenges the widely accepted idea that “absolute power corrupts absolutely.” Ten Brinke contends that this corruption only applies to the most malevolent individuals. Taking responsibility for one’s influence, or “barrel of apples,” requires self-discipline and honesty about one’s own character. Power, she explains, is inherently neutral; it amplifies existing traits.
Therefore, the societal challenge lies in cultivating “moral Machiavellis”—individuals who can strategically navigate complex situations with integrity. Such a development, ten Brinke suggests, would represent a significant improvement over a society that currently appears to be a fertile ground for cultivating psychopathic tendencies.
Further Reading on Deviant Behavior
Born Liars: Why we can’t live without deceit
By Ian Leslie. This book explores the pervasive nature of deceit, examining why lying is so compelling and its role as a developmental milestone.
Snakes in Suits: Understanding and surviving the psychopaths in your office
By Paul Babiak and Robert D. Hare. Building on Hare’s previous work, this book focuses specifically on non-criminal psychopaths commonly found in professional environments.
The Prince
By Niccolò Machiavelli. Originally written in 1513, this treatise on unscrupulous politics has evolved from a perceived endorsement of manipulation to a manual for self-defense against such tactics.
Sally Adee is a science writer based in London.