Yet another study carefully quantifies and confirms the obvious -- that people who base their career around wanting public adulation and attention tend to be (can you imagine it?) narcissists:

Celebrities have more narcissistic personality traits than the general population, and people with narcissistic tendencies seem to be attracted to the entertainment industry rather than the industry creating narcissists, according to a groundbreaking study conducted by researchers Drew Pinsky of the Keck School of Medicine of USC and S. Mark Young of the USC Marshall School of Business and the USC Annenberg School for Communication.

The study, which will be published in the Journal of Research in Personality (Elsevier), is the first systematic, empirical scholarly study of celebrity personality and was based on a standardized test of narcissistic personality traits administered to 200 celebrities....

"Narcissists generally crave attention, are overconfident of their abilities, lack empathy, and can evince erratic behavior," said Pinsky, who is an assistant clinical professor of Psychiatry at USC. "However, they are also well-liked, especially on first meeting, are extroverted and perform well in public." ....

"Our research also shows that many celebrities exhibit narcissistic behavior prior to becoming famous, which could indicate a self-selection bias for the entertainment industry by certain personality types," said Young...

Shocking, I know.

Media celebrities tend to be significantly more narcissistic than the general public. They also tend to lean much further left, politically. You do the math.