That’s because those situations lack “inferability,” says Roger Kreuz, a professor of psychology at the University of Memphis who has long researched sarcasm. Take talking to strangers: Without mutual understanding or inside knowledge, people you don’t know well have little basis for guessing you mean the opposite of what you’re saying. “You can’t be sarcastic with a stranger, or if you are, it’s a very formulaic sort of, ‘Lovely weather we’re having today’” on a gloomy day, Kreuz says. “With people you’ve known for a long time, anything goes. You can say the most ridiculous things and they’ll understand correctly, because you share common ground with them.” Without a shared frame of reference, sarcasm collapses into confusion, he adds.
Online platforms are especially tricky, because they’re “massively decontextualized,” Kreuz says. On Reddit, for example, everybody is a stranger, and it’s difficult to know for sure if a comment is earnest or ironic. Some posters try to counteract this by dropping a “/s” at the end to make their intent clear. Others are so mean-spirited, there’s no second-guessing what they mean. Walker points to a category of sarcastic remarks that are common across online forums: barbed compliments like “I’m so impressed with your ability to cut and paste links” or pointed jabs such as “Do you know how to read?” Others take the form of exaggerated politeness, like “Forgive me if I doubt your sincerity,” or “You are so smart!”