That cute little diagram of the tongue you might’ve seen in an elementary school science lesson, mapping out where tastebud receptors for sweet, salty, bitter, and sour are? It was all a lie, said Steven Munger, a professor at the University of Florida’s Center for Smell and Taste, in a recent Reddit AMA. “The tongue map was a mistake from the get-go … a mistranslation from the early 20th century (from a German manuscript, I believe),” Munger wrote. And yet it still pops up in textbooks today, even at the college level. The modern problem with the tongue map: It doesn’t account for umami, the savory flavor in things like Parmesan cheese that is now widely accepted by scientists who study taste and smell. (And we probably are capable of picking up on more basic tastes than that — like fat or starch, for example — but this hasn’t yet been extensively studied, he said.)
Each tastebud houses up to 100 taste receptors, and the idea that there are specific tastebuds or taste receptors for distinct tastes — and the notion that these are separated into four separate spots on the tongue — has been refuted at least since the 1970s. And yet the myth persists, even though it’s easy enough to disprove on your own, without the help of any specialized lab equipment: Put something salty, like a pretzel or potato chip, at the tip of your tongue, where the sweet receptors supposedly are. It will taste salty.