Old article and specifically only mentions NPD which is a highly problematic diagnosis because it only accounts for malignant narcissism and it doesn't account for the lack of diagnosis b/c narcissists don't seek treatment and there are many different types of narcissists.
Labeling 1/3 of everyone narcissists isn't helpful either. Every human has a balance of narcissism and self-loathing in them, and you can find narcissistic traits in nearly everyone if you look hard enough (ask leading questions in a survey). NPD is important bc it indicates harm.
1 in 6 people isn't a third of anything. Your math isn't mathing. And I'm quoting experts in the field, I'm not making anything up. And my degrees are in psychology. NPD is harmful but also rare. The vast majority of narcissists are not malignant narcissists. The diagnosis is misleading.