A swear word carries a strong emotional charge that other words don’t. You can see that from the research that shows that swearing can be useful in reducing pain*, and I doubt if I’m the only person who swears when I stub my toe.
The best explanation I’ve seen as to what makes a swear word centres around the idea that this is a taboo to protect society from a perceived danger.
For example, a taboo around not touching feces makes sense because human waste can be the source of illness. But then the words associated with feces start to evoke fearful feelings so it becomes taboo to use them.
The kind of things that taboos arise around can include
- bodily fluids (snot, urine, feces, blood)
- sex and sexual organs (which are also associated with defecation and urination)
because if you really believe in a deity, they can be quite dangerous too**.
If you look at the development of swear words their force seems to lessen over time. When I was a child, “bloody” was a very strong word and there was shock at hearing it for the first time on television. As time passes we become accustomed to hearing the words and now “bloody” is relatively mild. In the same way, the word “fuck” is becoming more prevalent and less shocking.
In the UK, profanities in the orginal sense of the word (i.e. religious words) are not seen as very strong language and “damn” and “hell” are considered quite mild. I think that’s because we’re not a religious society so no one really believes that any harm will come from saying them.
The words that cause shock and horror now are more likely to be racist or sexist epithets. My sense is that these words are genuinely harmful because of the effect on society of talking about other people in such a dismissive and disrespectful way. You’ll notice I’m not giving examples of those words, which just shows how powerful that particular taboo is.
**Forbidden Words: Taboo and the Censoring of Language
*Swearing 'helps to reduce pain'