It's been a long ride.
In 2007, my co-authors and I released data showing that narcissistic traits were higher in Generation Me than in GenX or Boomers. It was based on 85 samples of 16,000 American college students around the country who completed the Narcissistic Personality Inventory sometime between 1982 and 2006. The study was covered by the Associated Press and NBC Nightly News, and to my amazement both Conan O'Brien and Jay Leno made jokes about it. The paper was published in the Journal of Personality in 2008. http://dx.doi.org/10.1111/j.1467-6494.2008.00507.x
This being academia, someone (Kali Trzesniewski and Brent Donnellan) had to say we were wrong. These researchers found no change in narcissism in their dataset of students from University of California campuses, and their paper was published in the journal Psychological Science in early 2008. Just before it came out, a New York Times reporter called me, saying she was interested in the changes in the culture that led to the increase in narcissism. Only later did she call back to say the story would mention this (supposedly) contradictory data. I explained how the shift in ethnic composition at the UC campuses over time might have suppressed change and that the increase showed up in every other region of the country, but she chose to ignore that. When the NYT story came out, I was surprised and disappointed to see that its whole premise was that Trzesniewski and Donnellan were right and there was no change in narcissism.
My co-author Josh Foster then wrote to Trzesniewski and Donnellan to ask for their data separated by ethnicity. They graciously provided it, though they said the ethnicity data was only available for the 2002-2007 samples from UC Davis. When I opened their datafile, I was floored: Narcissism increased over time in every ethnic group. In other words, the researchers who told the New York Times and Psychological Science that narcissism hadn't changed were contradicted by their own data. So I guess we weren't so wrong after all.
Josh and I sent a paper based on these analyses to Psychological Science. Incredibly, the editor of the journal sent it to Trzesniewski and Donnellan for peer review (even though we had specifically asked that they NOT review it, as we guessed they would find it hard to be objective). On the basis of Trzesniewski and Donnellan's negative review, the editor of Psychological Science rejected the paper.
The Journal of Research in Personality (JRP) accepted and published the paper soon afterward:
Trzesniewski and Donnellan then published another paper, also in JRP, now saying that the ethnicity data had suddenly become available for a 1996 sample from UC Berkeley. This analysis showed a small increase in narcissism; they changed their argument from saying there was no change to that the change was small. They titled their paper "An emerging epidemic of narcissism, or much ado about nothing?"
But this analysis, like their original one, had a big problem: both of the early samples (1982 and 1996) were from UC Berkeley, and all of the later ones (2002-2008) were from UC Davis. So campus and time were completely confounded -- their effects could not be separated. Compared to students on other campuses, UC Davis students score much lower in narcissism, so this suppressed the change over time. Campus was an even bigger problem in their dataset than ethnicity. Because Trzesniewski and Donnellan apparently never analyzed their data within campus, they mistakenly concluded that there was no change over time. So did Brent Roberts, who published a re-analysis combining our data with Trzesniewski and Donnellan's. Because he didn't control for campus, he also mistakenly concluded there was no change.
With the addition of a simple control for campus (1 = Davis, 0 = not), the increase over the generations among 50,000 college students was clear. Josh also had data from his own campus, the University of South Alabama, from 1994 to 2009, and scores increased there too. That paper was published in January 2010 in Social Psychological and Personality Science:
And a study we had nothing to do with found a much higher lifetime incidence of Narcissistic Personality Disorder (NPD), the more severe, clinical form of the trait, among younger generations compared to older ones:
Now that a nationwide meta-analysis, two within-campus analyses, and a clinical interview study all show the same effects, the debate should be over. Let's move on to finding out what caused it.