Often, you can tell where someone grew up by the way they speak.

For example, if someone in the United States doesn’t pronounce the final “r” at the end of “car,” you might think they are from the Boston area, based on sometimes exaggerated stereotypes about American accents and dialects, such as “Pahk the cahr in Hahvahd Yahd.”

Linguists go deeper than the stereotypes, though. They’ve used large-scale surveys to map out many features of dialects. The more you know about how a person pronounces certain words, the more likely you’ll be able to pinpoint where they are from. For instance, linguists know that dropping the “r” sounds at the end of words is actually common in many English dialects; they can map in space and time how r-dropping is widespread in the London area and has become increasingly common in England over the years. 

In a recent study, we applied this concept to a different question: the formation of Creole languages. As a linguist and a biologist who studies cultural evolution, we wanted to see how much information we could glean from a snapshot of how a language exists at one moment in time. Working with linguist Hubert Devonish and psychologist Ewart Thomas, could we figure out the language “ingredients” that went into a Creole language, and where these “ingredients” originally came from?