A small group of hunter/gatherers living in the Amazon rain forest is overturning some fundamental assumptions about the mind. Although linguists have long believed that counting and having words for numbers are basic, if not innate, to human cognition, the Pirahã people in Brazil have no words to express numerical concepts such as “one,” “two,” or “many.” “They don’t count and they have no number words,” says MIT cognitive scientist Edward Gibson, who headed a study published in the journal Cognition [pdf].
The researchers spent eight days in a Pirahã rain forest village conducting counting tests on adult members of the tribe. Sometimes the experimenter placed varying numbers of spools of thread on a table and asked the participant to perform a simple one-to-one task, such as laying down the same quantity of uninflated balloons. Other tasks required remembering how many spools had been placed inside a can.
A previous—and contested—study of the Pirahã had reported that they used the words hói, hòi, and baágiso to represent “one,” “two,” and “many,” respectively. But Gibson’s tests revealed that the Pirahã actually used these words in a more relative way to mean “few,” “some,” and “more.” In some instances hói was used for quantities as large as six, and sometimes hòi—a similar but separate word—was used for quantities between four and ten. “None of the three words that the Pirahã produced were used consistently to refer to any particular quantity,” the researchers reported.
Gibson says his team is planning a follow-up study with Pirahã children. “We would love to test them,” he says, “but it may be difficult to get permission to go back to the village. If we can, we will.”