The aliens’ written language moved in circles, each sentence lacking a defined beginning or end. The alien visitors seemed to view time in a similar manner: as a circular concept.

Working to decode this mysterious language, accomplished human linguist Louise Banks—played in the sci-fi film Arrival by actress Amy Adams—begins to have visions of the past and future as her perception of time shifts from linear to circular. In other words, thinking in a different language causes her thought patterns to change. This is a core idea at the heart of the film: that an intimate relationship exists between the language you speak and the way you perceive the world.

The idea that “there’s a link between the shape of language and what people actually talk about,” actually has roots in 20th century linguistics theory, says Ives Goddard, a curator and linguist in the National Museum of Natural History’s Department of Anthropology. Known as the “Sapir-Whorf hypothesis,” this theory states that language doesn’t just give people a way to express their thoughts—it influences or even determines those thoughts. On the flip side, the evolution of a language is shaped by the culture and environment its speakers live in.

Yet most linguists put little stock in this hypothesis today. We asked a Smithsonian linguist and a Smithsonian anthropologist: Does the film’s central linguistic concept have any merit?

The Sapir-Whorf hypothesis is controversial on many levels, starting with its name. Linguists Benjamin Lee Whorf and Edward Sapir were close collaborators in the first decades of the 20th century, but they never actually published a hypothesis together about language and cognition. Sapir himself didn’t seem to fully embrace the ideas behind the hypothesis, according to Goddard, who has seen the film (and liked it). It was only after Sapir died in 1939 and wasn’t around to “rein him in,” Goddard says, that his student, Whorf, took Sapir’s thoughts in the more extreme direction that would later become enshrined in the theory named for them.

Whorf’s theory stemmed in part from his study of the Eskimo vocabulary for snow. Citing the work of Sapir’s mentor, anthropologist Franz Boas, Whorf argued that because the Eskimo people lived so intimately with the snow of the Arctic, they had developed far more terms to describe it than people of other cultures.

“We have the same word for falling snow, snow on the ground, snow packed hard like ice, slushy snow, wind-driven flying snow—whatever the situation may be,” Whorf wrote in the MIT Technology Review in 1940, a year after Sapir’s death. “To an Eskimo, this all-inclusive word would be almost unthinkable; he would say that falling snow, slushy snow, and so on, are sensuously and operationally different, different things to contend with; he uses different words for them and for other kinds of snow.” Inspired by Albert Einstein’s concept of relativity, Whorf called this concept “linguistic relativity.”

The exoticness yet simplicity of Whorf’s Eskimo snow example quickly made it a favorite trope among writers and would-be intellectuals. “We dissect nature along lines laid down by our native languages,” Whorf wrote. “The grammar of each language is not merely a reproducing instrument for voicing ideas but rather is itself the shaper of ideas.”

Linguistic relativity was packaged and popularized in the 1950s by some of Sapir’s other students. But in the following decades, the theory was ridiculed and dismissed by followers of the linguist Noam Chomsky, who argued that all languages share certain grammatical characteristics. Actually, Chomsky argued, human evolution and the brain have helped determine how languages are formed. “The more you examine Whorf’s arguments, the less sense they make,” linguist Steven Pinker scoffed in his 1994 book The Language Instinct.

Many critics of Whorf and linguistic relativity have accused him of misinterpreting Boas’ work and the Eskimo languages as a whole. In a provocative 1991 paper titled “The Great Eskimo Vocabulary Hoax,” University of Edinburgh linguist Geoffrey Pullum compared the Eskimo snow anecdote to the creature in the movie Alien, which “seemed to spring up everywhere once it got loose on the spaceship, and was very difficult to kill.”

“The fact is that the myth of the multiple words for snow is based on almost nothing at all,” Pullum wrote. “It is a kind of accidentally developed hoax perpetrated by the anthropological linguistics community on itself.”

By contrast, Igor Krupnik, curator and anthropologist at Smithsonian's National Museum of Natural History, asserts that the hoax is actually a hoax. In his 2010 book, Knowing Our Ice, Krupnik helped vindicate Whorf and Boas in part by documenting more than 100 terms for sea ice alone in the Yupik language. Krupnik argues that because some Eskimo people interact with the sea ice on a daily basis while hunting or sailing, it is natural that they would develop a specialized vocabulary to describe the many variations of sea ice and their associated dangers.

In recent years, some linguists have turned again to ideas of linguistic relativity. Linguist Lera Boroditsky, at the University of California at Santa Cruz, has done research showing that members of the Pormpuraaw Aboriginal tribe think about time passing differently than English speakers, because their language relates it to cardinal directions instead of from left to right. Yet some still say that Arrival goes too far: “they took the hypothesis way beyond anything that is plausible,” linguist and cognitive scientist Betty Birner said of the film in an interview with Slate.

While the specifics of the Sapir-Whorf theory are still viciously argued today, Goddard says that the film offers a thought-provoking example of how integral language is to our lives—and yet how little we know about how it works, even today. “It’s not really about aliens,” as Goddard puts it. “It’s about us.”