Benjamin Bergen swears, a lot (in his work, that is), and as the author of the new book What the F: What Swearing Reveals About Our Language, Our Brains, and Ourselves, he has been researching the use of offensive language and its human cognitive lifecycle. Not surprisingly, cursing is universal. Across the globe, his findings have identified four prevalent categories of taboo expletives: religious, sexual, bodily functions, and slurs. Bergen’s investigation also found that not all swear words are created equal, and some categories are far more offensive than others. For example, slurs (words that target specific groups of people) are considered the most offensive. There are also cultural differences. A word or phrase that is insulting in Italy may be benign in America.

To express something urgently, powerfully, and invoke an emotional response—that’s taboo language. There’s a secret science in profanity that they don’t teach in linguistics class.

So why do people curse? According to Benjamin Bergen, most swear words begin as harmless and functional. Their transformation into profanity comes through creative social slang. Eventually, the slang meaning takes over as the prevailing definition. After all, “cock” used to just mean rooster, and a thousand years ago, f*ck meant to hit, strike, or stab. Bergen adds that censorship of language is ineffective because like “whack-a-mole,” as soon as you strike one down, another pops up. It’s also true that once incendiary terms can devolve into the unprovocative.

Beyond their use as weaponized language, there is some good news regarding swear words. (Phew, since we all use them.) Bergen’s data reveals that profanity is often used to communicate excitement, love, or simply emphasis, and that there are health benefits. Cursing can relieve stress, motivate, and elicit the “fight or flight” effect with the release of adrenaline.

So go ahead, swear. In Benjamin Bergen’s professional opinion, these words and phrases aren’t inherently bad. What’s important is understanding their history and current power to identify the situations in which they may be appropriate or possibly incendiary and abusive.