So it turns out swearing is a sign of greater honesty. In fact, one study asked participants about their reasons for using profanity. Two of the main reasons were to express their emotions and to express their true selves.
These are preliminary studies and more research is needed. They are correlational, so we can’t say anything about causation.
There will still be people who swear a lot and are dishonest, along with those who swear very little and are honest.
Thanks for participating in the poll. Here is one of the studies:
Frankly, we do give a damn: Study finds links between swearing and honesty
https://journals.sagepub.com/doi/full/10.1177/1948550616681055