An article in Slate magazine points out that in the study that Joel Stein cites, researchers interviewed more than 30,000 participants to test them for symptoms of narcissistic personality disorder (NPD). The paper described the disorder as a “pervasive pattern of grandiosity, need for admiration and lack of empathy.” But many psychologists dispute the study. They point out that “there is no real way to find a definite measure for NPD among shifting cultural norms, and evolving technology”, according to Slate.