Can you think of a narcissist? Some people might picture Donald Trump, perhaps, or Elon Musk, both of whom are often labeled as such on social media. Or maybe India’s prime minister, Narendra Modi, who once wore a pinstripe suit with his own name woven in minute gold letters on each stripe over and over again.

But chances are you’ve encountered a narcissist, and they looked nothing like Trump, Musk or Modi. Up to 6 percent of the U.S. population, mostly men, are estimated to have had narcissistic personality disorder during some period of their lives. And the condition manifests in confoundingly different ways. People with narcissism “may be grandiose or self-loathing, extraverted or socially isolated, captains of industry or unable to maintain steady employment, model citizens or prone to antisocial activities,” according to a review paper on diagnosing the disorder.

Clinicians note several dimensions on which narcissists vary. They may function extremely well, with successful careers and vibrant social lives, or very poorly. They may (or may not) have other disorders, ranging from depression to sociopathy. […]