In the popular Netflix series, History of Swear Words, host Nicolas Cage explores the use – past and present – of the 6 most common expletives in the English language.  This documentary is the latest in a series of books, articles and studies that speaks to the unspeakable. Join us now for a 5-part anthology, as we jump on the naughty word bandwagon and delve deeper into the topic of cussing. In this first article, we look at swearing, its role in society and what science has to say about it.

Swearing – toddlers do it to get attention, teens to communicate their angst, adults to express frustration or bond with peers and apparently even monkeys have learned to sign what appears to be cussing.[1] It’s been around for ages, reflecting the taboos of the moment and changing along the way, as social norms and attitudes evolve. Believe it or not, science, once shy about exploring profanity, has actually been able to map out some aspects of the human brain thanks to swearing. Let’s see how the study of obscenities has played this important role.

Left brain = language, but not bad words

In Swearing is Good for You, author Dr. Emma Byrne tells the story of Phineas Gage, a railway worker who, in 1848, met with an unfortunate accident involving a metal rod that shot clean through his head. Amazingly, he went on to live another 12 years, but in that time, became a real potty mouth. The rod had destroyed his left frontal lobe, leaving the right side of his brain intact, suggesting for the first time in medical history, that the brain was not an undifferentiated mass of tissue but rather an organ with specialized areas responsible for specific tasks.

Right brain = emotions and swearing

As it turns out, swear words are processed differently by our brains than is other speech. Normally, the left side of the brain is in charge of language and other higher functions, while the right brain looks after emotions and lower brain functions. What researchers have found over time, however, is that patients who suffer damage to the left hemisphere (whether due to stroke or random metal rods) almost always retain their ability to swear, even after losing their capacity to speak.  On the other hand, people who suffer right brain damage tend to lose their ability to swear,[2] perhaps indicating that swearing is closer to our emotions than to rational thought. Why would that be?

What’s the point of swearing?

In her article on profanity[3], Tracy V. Wilson describes that swearing may be the grown-up version of crying as used by babies to express strong emotions. While swearing is slightly more complex than just a right brain vs left brain issue,[4] Wilson’s suggestion would support the notion that cursing is intimately connected to the right hemisphere. The idea of swearing as an emotional outlet may also explain how it can help us better tolerate pain and even avoid physical violence.[5]  While opinions vary in this respect, it’s clear that swearing still has a great deal to teach us about the brain and ourselves.

We’ve now only scratched the surface of what swearing has meant for human beings and science. What’s certain is that the use of profanity is much more than an indication of poor language skills, bad upbringing or lack of character. Less encumbered by moral dictates of the past, scientists can now continue learning about this taboo form of expression that has many people talking.

[1] Dr. Emma Byrne, Swearing is Good for You: The Amazing Science of Bad Language, Profile Books Limited, UK, 2017. Dr. Byrne reports that chimps who have been taught to sign actually use the word “dirty” in much the same way humans use swear words.

[2] D. Van Lancker, J.L. Cummings, “Expletives: neurolinguistics and neurobehavioral perspectives on swearing,” in Brain Research Reviews, 31 (1999), p. 86.

[3] Tracy Wilson, “How Swearing Works,” How Stuff Works, consulted on February 15, 2021,

[4] Swearing also involves other structures of the brain, such as the amygdalae.

[5] Alex Orlando, “Worried about swearing too much? Science says you shouldn’t be,” Discovery Magazine, January 14, 2020, consulted on February 18, 2021 at