The conversational idea of a toxic person can be traced to the clinical category of personality disorders, a nebulous set of diagnoses defined by supposedly lifelong, unchanging interpersonal dysfunction. Personality pathology, though treated as legitimate in mainstream discourse, is hotly debated by actual clinicians.
For example, narcissistic personality disorder is so contested that it was almost removed from a 2013 edition of the Diagnostic and Statistical Manual of Mental Disorders (the official US psychiatric disorders reference), partly because clinicians couldn’t agree what exactly it is. References to psychopathy, like toxicity, pervade pop culture despite the fact that there is no such diagnosis in official psychiatric manuals. The clinical tools for assessing psychopathy are fishy, yet this clinical flimsiness hasn’t diminished the concept’s prevalence.
Psychiatrist and historian Jonathan Metzl has extensively documented the ways that clinical categories develop and morph as culture changes. If YouTube self-help gurus and TV crime dramas tell stories about narcissism, psychopathy, or toxicity, we start to recognize the categories in real courtrooms, clinics, cubicles, and in our own lives.
So if narcissist and psychopath aren’t necessarily stable scientific categories, what do we know about people with difficult personalities? In general, people are malleable, and variations in context and experience can elicit highly varied behavior. Research suggests that even difficult personality styles can change over time, rather than being fixed and immovable. Intractable conflict experts don’t focus much on bad actors in part because they know that dynamics and situations are toxic, not people.