Chandler is standing on an icy pavement when Joey arrives to meet him. "Is Phoebe here with the cab yet?" Joey asks. It is a stupid question: there is no sign of Phoebe or a taxi. "Yeah," says Chandler.  "She brought the invisible cab. Hop in!"

Sarcasm has been defined as saying the opposite of what is true in order to make someone look or feel stupid.¹ This scene from Friends is a classic example.

Chandler has been called the most sarcastic character on TV.² His barbed remarks are a key part of the series' comedy. But in real life sarcasm can be very hurtful. The word in fact comes from a Greek verb meaning "to tear flesh".

Recognising its cruel side, officials in China are trying to change people's behaviour. They have issued a new set of rules for civil servantsAnyone working in a government department. The civil service has long-standing traditions and strict codes of conduct that can make it a law unto itself..

They include a list of banned phrases, such as "don't you understand Chinese?" and "there is a sign, read it."

Sarcasm is often said to be the lowest form of wit.³ But it has many defenders. The saying is sometimes completed with the words "but the highest form of intelligence".

Recent research⁴ has found that sarcasm can make people think more creatively. This is because the brain has to work harder to take in the difference between what is said and what is actually meant.

Students listening to a helpline proved much better at dealing with sarcastic complaints than with ones that were just angry. 

But the researchers add that you should be careful who you are talking to. Sarcasm is fine between people who get on with each other, like Chandler and Joey. But someone who does not like you or know you is likely to take it badly.

Writing in her blog, LK Greer agrees. But, she says, "sarcasm as a form of humour can be delightfully funny, illustrate the absurdityRidiculousness. of human behaviour, and even be educational."

Yes: Making fun of people is incredibly hurtful, and it is the weakest who usually suffer most. Those who do it pick on their victims' most vulnerable points, and sarcasm is the most horrible form of it.

No: Mockery can be gentle, and as a form of humour between friends it is fine. It can be a very good thing when it is directed against those in power or those who take themselves too seriously.   

Or... Whether it is right or wrong, it is part of human nature, and no one can ever change that. If we are going to get along with other people, we have to be able to take a joke.