More than irony: sarcasm

I have a Sheldon side, like the socially awkward character from the TV show The Big Bang Theory: like him, who is teased by his friends without realizing it, I often need someone to hold up a sign saying “Sarcasm” to help me. Even my children now have a better sarcasm detector than I do.

The problem is that if understanding irony is hard work, identifying sarcasm is even worse. In language, irony is the intentional use of words that have the opposite meaning to the one intended. Sarcasm, on the other hand, is the use of irony specifically with the intention of insulting someone or showing irritation or contempt.

A Japanese study published in 2013 explains why detecting irony and, even worse, sarcasm, is so hard for the brain. The study, which involved volunteers exposed to more or less ironic or sarcastic dialogues while inside a functional magnetic resonance imaging machine, showed that the process involves much more than simply registering incongruity between the words used and the context (such as saying that something obviously hideous is beautiful).

Understanding the irony of a comment involves activation of the superior temporal gyrus, a structure that allows the representation of the mental state of others, and thus the interpretation of others' intentions—such as to attack with words. At the same time, the inferior temporal gyrus, further down, and the medial prefrontal cortex, which represent the context of the situation, are active. If there is humor in the situation, activation of the dorsolateral prefrontal cortex increases. Conversely, the more emotionally striking the perceived irony, the greater the activation in the amygdala, which represents both one's own emotional state and that of others.

Understanding sarcasm, therefore, requires the integrated work of at least four distinct brain systems: those representing contradictions in language, the context of the conversation, and the intention and emotional state of the author of the sarcasm.

I have no problem understanding irony, and I appreciate its humor. But since I have difficulty identifying when the intention is negative, I find it exasperating to deal with people who abuse sarcasm. My solution is to surround myself with kind people, such as my husband and friends, who have noticed my tendency to look perplexed while trying to decide whether they are making fun of me or not, and who then hold up a little sign for me: “Sarcasm”...

Excerpt from Suzana Herculano-Houzel (2025) Neuroscience of Everyday Life, originally published in Folha de São Paulo in March 2014