More than 2 decades have passed since Geoffrey Saxe's first visit to Papua New Guinea, when he began his inquiry into the highly idiosyncratic counting system of Oksapmin's people. As evidenced by his account, a quarter of a century is a period long enough to make historical shifts visible. The point of departure for this commentary on…

This article extends a framework for the study of culture-cognition relations to problems of historical research and diachronic analysis. As an illustrative case, we focus on mathematics in Oksapmin communities located in a remote highland area in central New Guinea. The Oksapmin, like their neighboring Mountain-Ok groups to the West,…