First of all, it lets the other person know that you’re healthy. A person who does not fart at all isn’t eating much aside from refined sugars, so if you’re letting them rip, at least he/she know you take eating your vegetables seriously.⁠ ⁠ Second, a 2020 study found that the chemical compound AP39, linked to hydrogen sulfide (which causes unpleasant flatulence), is beneficial for cells. Most scientists will indeed stop short of telling you it’s good for you – but it’s not going to harm you, certainly.⁠ ⁠ Third, couples who laugh together stay together, and – setting aside whether or not laughing at farts is immature – farts are funny.⁠ ⁠ There have been studies done on fart humor, with one finding that humor is rooted in dominance, meaning that letting one rip is a (hilarious) way of asserting yourself. Another used the incongruity theory to state that inappropriate things often make us laugh. A third theory is that people laugh to relieve the awkward tension that ensues when another...