But Kluger also devotes a chunk of his book to what’s become a tired argument: The idea that Millennials—the generation that came of age with selfies and Facebook and the Kardashians—are the most self-absorbed generation of all. “Plenty of people are narcissistic in our society,” Kluger says, “but Millennials are doing these things on a pandemic level.”

Of course they are. They’re young and full of themselves, like every other generation that’s come before them was at some point. But are Millennials any more narcissistic than, say, the Baby Boomers, who were once considered the most self-obsessed cohort of their time? Consider the 1976 cover story of New York Magazine, in which Tom Wolfe declared the ‘70s “The Me Decade.” One could argue that every generation seems a little more narcissistic than the last, puffing out its chest and going out into the world with an overabundance of self-confidence, swagger, even a bit of arrogance. These traits are simply hallmarks of early adulthood—it’s often the first time people are putting themselves out there, applying for first jobs and meeting potential life partners. Overconfidence is how people muscle through the big changes.

Whether it’s Time’s 2013 cover story “The Me, Me, Me Generation” or Kluger’s book, the same statistics are cited as proof of Millennial narcissism. In a 2008 study published in the Journal of Personality, San Diego State University psychology professor Jean Twenge found that narcissistic behaviors among college students studied over a 27-year period had increased significantly from the 1970s. A second study published in 2008 by the National Institutes of Health showed that 9.4 percent of 20- to 29-year-olds exhibit extreme narcissism, compared with 3.2 percent of those older than 65.

But there’s a problem with all of this evidence: The data is unreliable. “It’s incredibly unfair to call Millennials narcissistic, or to say they’re more so than previous generations,” says Jeffrey Jensen Arnett, a professor of psychology at Clark University and author of Getting to 30: A Parent’s Guide to the Twentysomething Years. Arnett has devoted a significant amount of time and research to disproving the statistics that San Diego State’s Twenge has built a career on. He says that her assertion that narcissistic behaviors among young people have risen 30 percent is flimsy, since she’s basing it around data collected from the 40-question Narcissistic Personality Inventory (NPI), the results of which leave quite a bit up for interpretation. For example, does agreement with statements like “I am assertive” or “I wish I were more assertive” measure narcissism, self-esteem, or leadership?

Culturally, narcissism has become a catchphrase of sorts for traits people deem unpleasant or unlikable in a person, similar to how people will say they have obsessive-compulsive disorder just because they’re fastidious or detail-oriented, rather than because they meet the actual clinical diagnosis. If you love to talk about yourself, but you also show empathy for others, you’re not a narcissist. If you’re extremely confident at work but you’re good at accepting criticism, you’re probably not a narcissist either.