Sometimes certain things stick with me from a movie. For example, there is a scene in Amistad where the slaves’ lawyer and interpreter are trying to explain that they tried to do something for the native Africans. I forget now exactly what they tried to do – maybe it was get them freed or a new judge – but they were incapable of communicating the idea. You see, the African tribe had no word for “trying” or “attempting” to do something. One simply either does something or doesn’t.
Or, put more succinctly by a small, green puppet, “Do or Do Not. There is no try.”
It’s hard to imagine not being able to understand the meaning of an attempt, but what’s even harder is imagining not knowing the exact meaning of the word “seven.” Yet that’s exactly what cognitive psychologist Elizabet Spaepen of the University of Chicago discovered when she conducted an experiment with individuals who never learned the language of numbers.
Previous studies of tribes in the Amazon with no currency system – and no real reason to invent language to express exact numbers above five – hinted that language was closely related to understanding numbers. But the question of whether or not this conceptual barrier was due to language or a lack of cultural pressure was still open.
So Spaepen spent some time with a group of individuals in Nicaragua known as homesigners. This group of deaf individuals were first brought together in the 1970s where they spontaneously created a fully formed language. They subsequently went their separate ways, mostly using their newly created language at home with family members apart from each other. Thus, there are no consistent grammar rules or even a regular vocabulary; it’s whatever they’ve made up. And because they haven’t created words for numbers, they make a perfect test case.
In a new paper published in the Proceedings of the National Academy of Science, the researchers told them animated stories that involved specific numbers, such as eight frogs on a lily pad, four jump away all at once, and then return two at a time. When asked to recount the story to a family member, the signers could not get the number of frogs correct.
In another experiment, Spaepen showed them a line of poker chips and then asked them to duplicate it. When the original line was still visible, the homesigners had no problem lining up a new line one-to-one. But when it was covered, they couldn’t manage the task. They appeared to use their fingers to represent individual objects, i.e., index finger for blue chip, middle for red, ring for another blue, etc. They weren’t using their fingers to actually count.
Or, as Spaepen said, “They can’t represent something like exactly seven. What they have is a representation of one-one-one-one-one-one-one.”
“Language input is important for everybody’s representation of number, and how counting works,” Spaepen said. “This isn’t something you just get for free because you’re human. It depends on the quality and amount of input you get. If you’re not getting it in your language, you’re not going to just come up with it on your own.”