The phenomenon is truly global. According to Davies’ research, Uzbeks get made fun of in Tajikistan while in France, it’s the French-speaking Swiss. Israelis rib Kurdish Jews; Finns knock the Karelians, an ethnic group residing in northwestern Russia and eastern Finland. The Irish, it turns out, have a particularly bad lot. Dumb-Irish jokes are equally common in England, Wales, Scotland, and Australia. Although it could be worse: If you happen to be an Irishman from County Kerry, you even get made fun of by your fellow Irishmen as well. The model even extends to the work world: Orthopedic surgery might be a highly competitive field, but other surgeons deride such rough-and-tumble musculoskeletal work as inferior. (“What’s the difference between an orthopedic surgeon and a carpenter? The carpenter knows more than one antibiotic.”)

“Nearly every country has stupidity jokes,” Davies told us when we visited him in Reading, England. The fact that he’s uncovered a nearly universal kind of joke is all the more incredible considering the vast majority of humor is the opposite of universal. There’s a reason that action films are far more likely to be global blockbusters than comedies. Humor is incredibly subjective—what you find funny varies immensely by upbringing, age, gender, political affiliation, and a host of other factors.