HOLLYWOOD — Let's say there's a famous movie star who thinks he owns Malibu, or a big-name actor who holds himself out as an expert on psychiatry on national television. Or maybe there's a famous actress who frequently calls in sick to the movie set, costing producers thousands of dollars, because she is tired (or hung over). Aren't these examples just proof that celebrity and narcissism go together like Paris Hilton and paparazzi?

Not really. They're just anecdotes.

What was always lacking — until last week — was scientific proof that celebrities are more narcissistic than the rest of us. At last, thanks to a first-of-its-kind study, we don't have to rely on reports from the Malibu sheriff's substation or US Weekly to confirm what the anecdotes seem to be telling us.

Du-uh, you say? Not so fast.

According to the study's authors, Drew Pinsky, internist, addictionologist (yes, it's a word), University of Southern California assistant clinical professor of psychiatry and host of the long-running call-in show "Loveline"; and S. Mark Young, a USC professor of sports, entertainment, accounting and communications, no one had conducted an academically rigorous study of celebrity personalities — because nobody ever could.

Stars, they point out, live in bubbles of publicists, agents and managers, which is not conducive to psychological probing.

"No one has ever had access to them," Pinsky said. "I have a group of them every night on my radio show."

Dr. Drew, as he is known to "Loveline's" listeners, has spent years taking calls from confused kids about drugs, sex and relationships. Always at his side: guests — an actor, a musician, a band, a comedian or (more recently) a reality-TV star — and a very annoyed co-host, Adam Carolla, who resented the scientific intrusion as Pinsky culled data.

The study — soon to be published in the Journal of Research and Personality — confirmed that celebrities are more narcissistic than average Americans. And — surprisingly — they seem to start that way, leading Pinsky and Young to surmise that narcissistic people seek careers in the limelight, rather than become narcissistic when they earn fame. Young thinks this nugget might prove useful to the increasingly popular course of study known as entertainment management.

The average Narcissism Personality Inventory score of Americans — as demonstrated in a previous study — is 15.3 out of a possible 40. Celebrities averaged 17.8. Contrary to what occurs in the general population, women celebrities, across the board, were more narcissistic than males (19.26 versus 17.27). Musicians — who have the highest skill level — are the least-narcissistic celebrity group, while reality-TV stars — the least talented or skilled group — are the most narcissistic.

"Female reality-show contestants," Pinsky said, "are off the chart." (Omarosa, anyone?)

"I was sort of amazed by this study," said narcissism expert W. Keith Campbell, associate professor of psychology at the University of Georgia and author of the 2005 book "When You Love a Man Who Loves Himself."

"Usually we study undergraduate psychology students or do anonymous Internet surveys," he said. "To get celebrities is really hard to do."

Researchers distinguish between normal or healthy narcissism and excessive narcissism, sometimes called narcissistic personality disorder, which Pinsky and Young did not attempt to measure. They also cautioned against conflating egotism and narcissism. Narcissistic people have low self-esteem and are compensating for it, he said; egotists genuinely love themselves.

Nearly all of the guests whom Pinsky asked on a random basis agreed to participate. Although he and Young pledged confidentiality, Pinsky said many didn't care whether they were anonymous. Many, he added, realized they were not entirely normal, personality-wise, and were curious about what was going on. Young crunched the numbers.

The results, hoped Pinsky and Young, might help a celebrity-obsessed world understand what makes these people tick.

"I guess we chose to focus on narcissism because you keep hearing and reading in publications all this speculation about how these people acquire narcissistic tendencies by virtue of being celebrities," Pinsky said. "To say celebrity is the reason for their pathologies is ridiculous. Their greatest fear is losing their celebrity status." He hypothesized that for some, fame is a bromide for psychic pain and emptiness stemming from childhood trauma, such as abuse or other attachment issues.

For his part, Young has been developing an entertainment management program at USC's Marshall School of Business and felt that studying celebrities could help fill some gaps. "A key goal for me," Young said, "is to provide a clearer understanding of the celebrity personality so that future and current business people in the industry will be better able to work with and manage them."

Over a recent 20-month period, before Carolla left "Loveline" to start a morning-drive show, 200 actors, musicians, comedians and stars of reality TV took the Narcissism Personality Inventory, a 40-item survey that is a standard psychological tool. The NPI asks respondents to make a "forced choice" between two statements.

Examples include: