Mention celebrity anger and most people think of public brawls with pushy paparazzi, or outrage at intrusive fans.
But there is another kind of celebrity anger, away from the public eye — like when Alec Baldwin couldn't reach his 12-year-old daughter on the telephone and he left her a message of fury.
"I'm gonna straighten your a— out when I see you. Do you understand me?" Baldwin said in the message. "I'm going to really make sure you get it so I'm going to let you know just how I feel about what a rude little pig you are."
Robert Millman, a professor at Cornell's Weill Medical College, said that he's identified a psychological syndrome unique to celebrities that helps explain this rage. He calls it acquired situational narcissism. It starts with huge success.
"It's this huge rage that you're not as great as you could be, or you're not being perceived as great as you could be. They don't know how wonderful you are," Millman said. "You can be a Saudi prince, for example, or you can be a baseball player or you can be a random billionaire and you can develop malignant narcissism by virtue of the situation."
Actress Lily Tomlin and disc jockey Casey Kasem were caught on tape lashing out at their co-workers.
Russell Crowe hurled a phone at a hotel employee while trying to place a call.
"The lack of empathy is eerie. That they think they're right and that the desk clerk or the whoever just didn't understand how important their needs were," said Millman, who explained that narcissism leads to depression, isolation, rage and envy.
Consider catwalk queen Naomi Campbell. She attacked a fellow passenger on a flight who tried to take her picture.
Her fiery side landed her a stint with the New York Sanitation Department after she threw her cell phone and hit her housekeeper.
"What I was afraid of, it was her swings," said Gabby Gibson, another former Campbell maid. "Physical swings."
Gibson says she was struck by the supermodel while they were searching for a lost pair of her jeans.
"So I kneel down on my knee and she came from behind and swing in my — in the back of my head. And I ask her, what for are you hitting me?" said Gibson.
Now Gibson is hitting back by suing Campbell but Campbell denies Gibson's allegations.
But it's not just famous people who exhibit anger and narcissism, according to University of Michigan professor Brad Bushman. His test data say narcissism in America is increasing, particularly among the young.
"There's something about this American culture that seems to feed these narcissistic tendencies," Bushman said. "The changes in the Internet like Facebook and MySpace and YouTube — but it's also reflected in television programs, all these reality shows where people can become stars."
To show the link between high levels of narcissism and anger, Bushman has done studies of thousands of students. He did a demonstration for "20/20." He asked a group of students who scored either high or low on narcissism scales to write an essay. When they got it back, they saw that someone had given their essay a bad grade.
To measure their anger, students were asked to help make lunch for the person who'd graded their essays. They were informed that the grader hated spicy food, so researchers took note of how much hot sauce each student put into their grader's food.