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Numerical cognition: Adding it up.

In this article, I provide a historical overview of the field of numerical cognition. I first situate the evolution and development of this field in the more general context of the cognitive revolution, which started in the mid-1950s. I then discuss the genesis of numerical cognition from 6 areas: psychophysics, information processing, neuropsychology, mathematics education, psychometrics, and cognitive development. This history is personal: I discuss some of my own work over the last 30 years and describe how each of the authors of the articles in this collection originally connected with the field. One important goal of the article is to highlight the major findings, both for experts and for those who are less familiar with research on numerical processing. In sum, I sketch a context within which to appreciate the neural, computational, and behavioural work that the other 4 authors summarise in their articles in this special section.