Anyone who’s frozen up during a job interview, a grade-school theater performance, or what would otherwise have been an irresistibly suave and witty pick-up line knows how paralyzing it is to truly be “at a loss for words.” Luckily, the experience is a temporary one, and before long the language that has inundated your life since you were little comes flooding back. But what if you grew up without any words at all? It’s pretty much impossible to imagine living in a world without words, but here at AAAS, “Thinking With and Without Language” took a peek at the thoughts of some people who happened to grow up without the privileges of language.
“Home signers” are deaf people who grow up without any language input (they don’t learn sign language, and they can’t hear or read) so they invent gestures to communicate. These “bare bones” gestures so don’t include notions like numerical relationships (such as less than and more than), so Elizabet Spaepen from the University of Chicago studies them to see how their limited “language” ability affects their ability to think of higher numbers. The idea is based on the Whorf hypothesis–the theory that language has a heavy hand in shaping thought.
The theory was recently strengthened by a high-profile Science paper (pdf) by Peter Gordon that came out in 2004, which looked at the Pirahã culture, whose number system consists of “one,” “two,” and, well, “many.” They don’t have the vocabulary to describe anything greater than two with any precision. And to make things more complicated, the word for one can also mean “roughly one,” and the word for two can also mean “not many.”
Gordon wondered whether their limited numerical vocabulary might limit their ability to think of higher numbers, so he performed the following test: he laid out up to eight objects in front of him on a table, and asked the Pirahã to place the same number of objects on the table. Although the Piraha did fine with 1, 2, and 3 objects, their accuracy dropped steeply once the number of objects exceeded 3, supporting, according to Gordon, “linguistic determinism.”
But today, Spaepen addressed a caveat to this conclusion, which had previously been voiced (pdf). She pointed out that the Pirahã people don’t really need numbers or counting; they’re a culture of hunter-gatherers who rarely trade, so numbers don’t factor into their lives. So the question is: do they have a poor concept of numbers because of their limited language, or because they never get to practice?
Spaepen was able to separate language from culture by comparing the Pirahã people to Nicaraguan home signers, who lack numerical vocabulary but exist in a society in which numbers and counting are important. Spaepen assigned these home signers the same tasks that Gordon assigned the Pirahã, and found that the home signers perform at the same level as the Pirahã—even when the home signers use their fingers to count. These results suggest that cultural support and practice are not sufficient for developing a concept of numbers and counting, and it follows that numerical language is indispensable for numerical cognition. So it seems that Whorf’s hypothesis, and Gordon’s initial conclusion, have passed yet another test.