By Matthew Davis
BBC News Online
Tempers boiled over during South Korea's impeachment row
Politics has been described as "war without bloodshed", but there is a fine line between verbal confrontation and physical violence, as recent parliamentary conflicts show.
Scuffles in the Taiwanese parliament and boiling tempers in South Korea have turned the spotlight on MPs who have destroyed the normally rarefied atmosphere of the debating chamber.
Taiwan's parliament has a history of fist-fights. In 2001 MP Lo Fu-chu was suspended for six months after punching a female colleague in a row at a committee meeting.
Dr Gerald Chan, at the Centre of International Studies at Cambridge University, said many fledgling democracies - like unruly teenagers - were just going through a stage.
"In a young democracy, things can happen that way. If we compare Taiwan to the British or US parliaments, they have been through that stage of democracy and have come out the other side.
"You can see the same sorts of incidents happening in South Korea and I can see this sort of thing happening again in the future, especially when you have very divisive issues and tight votes.
Taiwan's is a fledgling democracy
But similar scenes happen the world over. Russia's parliament has exploded into brawls in the past, particularly in the early 1990s.
A session of the Italian parliament was suspended in 1998 when a row over a football refereeing decision came close to an all-out brawl between two MPs.
And a famous row in the UK in 1976 ended with MP Michael Heseltine seizing the chamber's ceremonial mace and - according to the most colourful accounts - flailing it about his head.
In November 2001, scuffles erupted outside the Stormont assembly as David Trimble was re-elected as Northern Ireland's first minister.
But the confrontational nature of politics, and the high stakes, leave violence simmering beneath the surface, however august the chamber.
Government and opposition MPs in the British parliament are divided by a space two sword-lengths apart, a throwback to the days when weapons were routinely carried.
British MPs are kept two sword lengths apart
Professor Windy Dryden, a psychologist at London's Goldsmiths College, says a number of key ingredients are usually present before an argument descends into physical confrontation.
Among them is the "absolute conviction that the other person is wrong and must not be allowed to get away with it," Prof Dryden said. "There must also be a sense that it is acceptable to express oneself in that way."
The sight of politicians brawling evokes strong reactions in countries where such behaviour is unusual, because it falls outside of "cultural contexts" the professor says.
"But we have to make the distinction between genuine violence, and anger that is produced for a purpose," he added.
Of course, MPs are only doing a job like the rest of us, and research by occupational psychologists may have found the reason behind many incidents.
The British Psychological Society discovered cheating, lying and "incredibly loud" colleagues were behind most of the pent-up anger in the workplace.