Most of the time, when you say something sarcastic, the person that you're speaking to understands your intention. But how? Since they can't rely on the words for the message, listeners pick up on other cues. When we say something sarcastic, we often use a very specific tone of voice. Important elements of spoken sarcasm include intonation, or how you vary the pitch of your voice, and stress, or how you emphasize certain words.
When English speakers express sarcasm with the word "Thanks!", they often use a nasal tone. Some researchers say that this nasal tone shows a connection between sarcasm and extreme disgust, to the point where the speaker is "expelling something nauseating" and he or she wants to remove it not only from the mouth but also from the nose" [source: Haiman].
Sarcasts of all languages use what Haiman calls inverse pitch obtrusion. This occurs when the speaker pitches a stressed syllable lower than the other words in the sentence. Take our weather example from the last section:
The pitch of the word "great" in this sentence changes depending on whether you're being sincere or sarcastic. A sarcast might also stress the word "great" heavily, to show that it's anything but great.
We also express sarcasm by elongating our words ("Well, excuuuuuse me!") or saying words that normally express excitement in a very flat or apathetic way, such as "Wow." or "Yay." Finally, we might express sarcasm by using a sing-song melody, such as in "sor-eeee!"
Even if you didn't pick up on any of these vocal cues, you might be able to tell when someone is being sarcastic by context. If you spend most of a conversation talking about how terrible your mother is at gift giving, and then end with "I just loved my birthday sweater," listeners will probably know that you didn't care for it at all. Finally, you can often tell a sarcast by his facial expression -- usually one of disgust, irritation or apathy.
Sarcasm exists in many languages other than English; in fact, speakers of many foreign languages even use the same types of indicators that we do in English. Haiman points to examples in Italian, German, Japanese and Mandarin.
So most adults can pick up on these cues to infer sarcasm, but what about children? Researchers disagree on exactly when children begin to infer sarcasm: Some believe that younger children mainly tell sarcasm by the context, while intonation comes into play with older children. Others believe the opposite.
A study of French-speaking children in 2005 showed that the younger children (age 5) understood sarcasm when the speaker used a sarcastic intonation, while the older children (over the age of 7) could tell sarcasm simply by the context [source: Laval]. When children don't successfully interpret a statement as sarcastic, they sometimes interpret it as a lie, especially when the only cue is contextual. As of yet, there is no one age when children understand sarcasm; in some studies, children as young as 3 years old could tell when someone was being sarcastic.
Some people, regardless of age, never understand sarcasm. Autistic people, for example, may have difficulty understanding sarcasm because they can't grasp the complex relationship between language, intention and context. Problems with understanding sarcasm may also have to do with lesions in the brain or brain damage.
A 2005 study in Neuropsychology concluded that three areas of the brain are responsible for our understanding of sarcasm: the language cortex in the left hemisphere, the frontal lobes and right hemisphere and the right ventromedial prefrontal cortex. When you hear a sarcastic statement, the language cortex understands its literal meaning. Then the frontal lobes and right hemisphere infer its context. Last, the right ventromedial prefontal cortex put the two together and interprets the statement as sarcasm.
In the next section, we'll look at the history of sarcasm in literature.