Using Mental Representations of Space When Words Are Unavailable: Studies of Enumeration and Arithmetic in Indigenous Australia

Here the authors describe the nature and use of spatial strategies in a standard nonverbal addition task in two groups of children who speak only languages in which counting words are not available, as compared with children who were raised speaking English. They tested speakers of Warlpiri and Anindilyakwa aged between 4 and 7 years at two remote sites in the Northern Territory of Australia. These children used spatial strategies extensively and were significantly more accurate when they did so. English-speaking children used spatial strategies very infrequently but relied on an enumeration strategy supported by counting words to do the addition task. The main spatial strategy exploited the known visual memory strengths of Aboriginals and involved matching the spatial patterns of the augend and addend sets. These findings suggest that counting words, far from being necessary for exact arithmetic, offer one strategy among others. They also suggest that spatial models for numbers do not need to be one-dimensional vectors, as in a mental number line (MNL), but can be at least two-dimensional.