Rocky Road is just a good name for an ice cream flavor. So good, in fact, that two ice cream institutions have dueling claims to Rocky Road’s invention. It’s a story of alleged confessions and a whole lot of ice cream-fueled drama. If it were just the flavor that made Rocky Road so special, every company could have just made their own concoction of nuts, chocolate, and marshmallows, named it “Muddy Street” or “Pebble Lane,” and called it a day. But there’s a linguistic reason why Rocky Road just sounds so dang delicious—and it’s studied by linguists and marketers alike.

Fenton's Creamery in Oakland, California, one of the institutions that lays claim to inventing Rocky Road.

In this episode, we mention the Bouba Kiki Effect. Imagine two shapes: One is a pointy, jagged polygon, the other an ameboid-like splotch. Which shape would you name “Bouba,” and which would you name “Kiki?” In study after study, 90% of people agree—the pointy shape is “Kiki” and the rounded shape is “Bouba.” This so-called “Bouba-Kiki Effect” holds in many languages, and has even been demonstrated with toddlers. But why the near-universal agreement? Cognitive psychologists like Kelly McCormick have several theories. Watch this Science Friday video to learn more. 

Alissa Greenberg is a freelance journalist. 

Dan Jurafsky is a professor of linguistics at Stanford, and the author of The Language of Food. 

Will Leben is professor emeritus of linguistics at Stanford, and is the former director of linguistics at Lexicon Branding. 

Read Alissa Greenberg’s full (highly entertaining) story of the history of Rocky Road ice cream. 

The Language of Food by Dan Jurafsky is a word nerd’s dream, and contains more about his experiment on cracker and ice cream brand names. 

Science Diction is hosted and produced by Johanna Mayer. Our editor and producer is Elah Feder. We had additional story editing from Nathan Tobey. Fact checking by Michelle Harris, with help from Danya AbdelHameid. Daniel Peterschmidt is our composer. Sound design and mastering by Chris Wood. Our Chief Content Officer is Nadja Oertelt.