Incivility cut a wide swath through the American landscape this past week.

In sports, Serena Williams cussed out a line judge at the U.S. Open tennis tournament after the official called a foot fault when the game was on the line. Her outburst was profane enough to be unprintable in a family newspaper.

In entertainment, rapper Kanye West jumped on stage and grabbed the microphone from country star Taylor Swift at the MTV Video Music Awards in the middle of her acceptance speech for best female video of the year, yelling, in effect, that Beyonce should have won.

In politics, U.S. Rep. Joe Wilson, R-S.C., called out that Barack Obama was a liar during the president's speech to a joint session of Congress.

What's with all the rudeness? Is this just a random cluster of temper tantrums or publicity stunts? Or has our public discourse turned so mean that disrespect and contempt are seen as virtues instead of vices?

Probably not the latter. All three of the offenders are paying a price for their bad behavior. All were booed and roundly rebuked. All apologized, sincerely or otherwise. Ms. Williams' outburst cost her the match, plus a fine for unsportsmanlike conduct. Mr. West was hooted off the stage and has been dumped on by a Who's Who of stars. Mr. Wilson may still be subject to a congressional reprimand. Apparently, there remain some lines that shouldn't be crossed.

If Mr. West was trying to tear down Ms. Swift, it didn't work. On the contrary, the country music singer was elevated to near-martyr status by his attack. Likewise with Mr. Wilson and the president, whose approval ratings were higher after the speech than they were beforehand.

"The fact that these situations have provoked such an outcry shows a wide agreement that these behaviors are inappropriate," said Elizabeth Howell, spokesperson for the Emily Post Institute.

The three outbursts don't have much in common beyond their rudeness, she said.

"Serena's in a competitive athletic event. Her adrenalin is running, it's very intense. The outburst is still not appropriate, but it is understandable."

With Mr. Wilson, she said, "We think he had a Homer Simpson moment. He thought a lot of people would be yelling but his turned out to be the only voice in the room. His foot was in his mouth and he was pretty embarrassed."

As for Mr. West, she said, "The guy's a jerk, and it's not the first incident." (The Daily Beast posted an online gallery of "Classic Kanye West Freakouts" yesterday.)

The good news, Ms. Howell said, was the way Beyonce reached out to Ms. Swift and brought her back up to the spotlight to finish her acceptance speech.

"That was a class act," Ms. Howell said. "If that hadn't happened, people would have gone away with a much worse feeling."

Taken together, though, don't these incidents demonstrate a new low in behavior?

"People always say that the current time period is so much ruder than in the past," Ms. Howell said. "That's been going on ever since Emily Post published her first book in 1922."

Indeed, a 2002 national study titled "Aggravating Circumstances: A Status Report on Rudeness in America," showed that 79 percent of respondents said people are less considerate and more selfish in general. The report, by the research group Public Agenda, described disrespect, lack of consideration and rudeness as serious and pervasive.

At the same time, only 41 percent admitted being rude themselves.

In other words, "other people are rude, but my behavior is justified," said Pauline Wallin, a clinical psychologist in Camp Hill, Pa., and author of "Taming Your Inner Brat: A Guide for Transforming Self-Defeating Behavior."

"When someone else does something we consider wrong, we tend to blame their personalities. When we do it ourselves, we blame circumstances. For example, if my kids spill juice, they're being clumsy. If I spill it, I was distracted. Other people don't get the pass we give ourselves."

The "inner brat," Dr. Wallin said, is "the part that wants what it wants when it wants it and doesn't care who or what is destroyed in the process.

"It's the part that's still self-centered, like a 2-year-old. We learn coping skills as we get older -- waiting our turn, delayed gratification, consideration of others. But when we're under stress, that can go out the window and we become self-absorbed and demanding."

The behavior is ultimately self-defeating, she said. "Relationships require give and take. When it's all about you, people don't want to stick around."

That's a real danger for celebrities, she said. "When their entourage makes it all about them, they live in a sheltered world surrounded by yes men. They get into trouble a lot because in the eyes of those surrounding them they can do no wrong."

The outside world, however, is rarely so forgiving.