Five years ago cognitive scientist Rafael Núñez found himself in the Upper Yupno Valley, a remote, mountainous region of Papua New Guinea. The area is home to some 5,000 indigenous people, and Núñez and his graduate student, Kensy Cooperrider, were studying their conceptions of time.

Most of you reading this post have a Western understanding of time, in which time has a spatial relationship with our own bodies. The past is behind us, the future ahead. I look forward to Christmas and reach back into my memories. But that particular cognitive framework is not universal. Núñez’s work has shown, for example, that the Aymara people of the Andes think about time in the opposite way; for them, the future is behind and the past lies ahead.

An anthropologist working in Papua New Guinea, Jürg Wassmann, suspected that the Yupno have yet another way of thinking about time, and invited Núñez and Cooperrider to come down and investigate. The Yupno have no electricity and no roads; getting to a city involves a several-day hike. They live in small thatch huts surrounded by green mountains. This rolling landscape, the researchers discovered, is what centers the the Yupno’s conception of time. For them, the past is downhill and the future uphill.

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View Images Above, homes in the Upper Yupno Valley. Photo by Rafael Núñez. Below, a Yupno man talks about the future. Photo by Kensy Cooperrider.

Núñez and Cooperrider figured this out by analyzing the way the Yupno point during natural speech. And in the midst of doing those experiments, the researchers stumbled onto something else unexpected: The Yupno don’t point like Westerners do.

We Westerners have a boring pointing repertoire. Most of the time, we just jut out our arm and index finger. If our hands are occupied — carrying a heavy load, say — then we might resort to a jerk of the head or elbow. But if the pointer finger’s free, we’ll point it.

Not so for the Yupno. Within a few days of their arrival in the valley, Núñez and Cooperrider noticed that the Yupno often point with a sharp, coordinated gesture of the nose and head that precedes them looking toward the point of interest. Here’s how the scientists described the nose part of the gesture, dubbed the ‘S-action’, in a 2012 paper:

The kernel of the nose-pointing gesture is a distinctive facial form that is produced by a contraction of the muscles located bilaterally on both sides of the nose, which raise the upper lip and slightly broaden the wings of the nose,” they write. “Informally, the combined effect of pulling the nose upward and pulling the brow downward and inward may be characterized as an effortful scrunching together of the face.

Last year Núñez and Cooperrider made a second trip to the Yupno Valley to get a better understanding of how often the Yupno use the S-action, and why.

For this study (which was funded by the National Geographic Society), the researchers designed a game in which two people must work together to put various colored blocks into a particular configuration. One person, the director, sees a photo of the target configuration and then instructs the other person, the matcher, on where to move the pieces to make them match the photo.

The game presents a tough communication challenge that players meet by using lots of demonstratives (“This one over here!”, “That one over there!”) and frequent pointing, Núñez says.

The Yupno tend to use nose pointing more than finger pointing, as Cooperrider reported at the Cognitive Science Society meeting in July. That sharply contrasts with what the researchers observed among college students playing the same game in Núñez’s lab at the University of California, San Diego. Westerners, in the researchers’ words, “stuck unwaveringly to index finger pointing.”

View Images A California college student (top) and a Yupno man (bottom) play the communication game. From Cooperrider et al, 2014

OK, so culture seems to affect pointing behavior. But there are lots of ways in which Westerners are different from the Yupno. Why, I asked Núñez, should we care about pointing?

Pointing, he answered, seems to be a fundamental building block of human communication. Great apes are never seen pointing in the wild. And in human babies, pointing develops even before the first word.

If we want to understand why people point, then it’s critical to look at how all people point, not just the WEIRD (Western, educated, industrialized, rich, democratic) ones. “If we want to understand human evolution and human minds, we need to really look at variety,” Núñez says. And whatever theories researchers come up with to explain the evolutionary or neural roots of pointing, “they would have to be able to explain all of these different forms.”

The Yupno aren’t the only ones who point with their face. Lip pointing — in which protruding lips precede an eye gaze toward the area of interest — has been observed in people from Panama, Laos, and other groups in Australia, Africa, and South America. Head pointing, according to one study, happens frequently among people speaking Arabic, Bulgarian, Korean, and African-American Vernacular English.

Núñez speculates that early human ancestors used a wide variety of pointing gestures, and these have been shaped and pruned over time depending on the needs of a particular culture.

He doesn’t know why the Yupno prefer nose pointing, but speculates that it could be related to their penchant for secrecy. On the second day of his first visit, Núñez was walking through the woods with about 25 children behind him. He was struck by their quiet: For the entire 30 minutes, the children were whispering. He soon noticed that Yupno adults did it, too. “The amount of whispering that we observed in this community is unbelievable,” he says.

So perhaps the S-action is a way to convey meaning in a less showy way than extending an arm that everyone can see. “In this community, it’s very important to know who’s saying what to whom and about what and at what time,” he says. “There are a lot of cases where you don’t want to be seen saying something to somebody.”

But that’s just a hypothesis. Also mysterious: Why did Western culture lose its pointing variety?

Actually, Núñez muses, we may still be evolving on that front. Consider someone at a conference presenting information to several hundred people. What do they use? A laser pointer.