Proceedings of the Annual Meeting of the Cognitive Science Society

Cognition and culture shape each other. Private thinking is externalized in public artifacts, which can shape habits ofthought. Within individual minds, for instance, numbers are associated with space. Do similar regularities exist withinthe cultural ecosystem of written numbers? We analyzed three contexts: English books, childrens picture books, andalgebraic expressions created during mathematical activity. Within individual numbers, digits were ordered spatially fromleft-to-right, with lower-value digits appearing more often to the left and greater-value digits to the right (e.g., 179). Ona larger scale, lesser-valued numbers were more likely to appear first in phrases and algebraic expressions (e.g., 19 dogsand 32 cats, 19x+32). The cultural ecosystem of number thus exhibits spatial regularities at multiple scales. We discussimplications for the development and dissemination of individual mental associations (mental number lines) and defend anecological perspective in which cognition reflects mutual constraints between artifacts, practices, and individual thought.