Karenleigh A. Overmann
Karenleigh A. Overmann is a cognitive archaeologist known for her work on how ancient societies became numerate and literate. She currently directs the Center for Cognitive Archaeology at the University of Colorado, Colorado Springs. Before becoming an academic researcher, Overmann served 25 years of active duty in the U.S. Navy.
Education
Overmann completed her master's in psychology in 2013 at the University of Colorado, Colorado Springs, under the supervision of Frederick L. Coolidge and Thomas G. Wynn and her doctorate in archaeology in 2016 at the University of Oxford as a Clarendon Scholar under the supervision of Lambros Malafouris and Chris Gosden. From 2018 to 2020, Overmann was a Marie Skłodowska-Curie Actions postdoctoral research fellow at the University of Bergen.Work on numeracy
Overmann has published several works showing how numbers are realized and elaborated through the use of material forms; these make the innate sense of number tangible and tractable to manipulation. She describes the role of "the material devices used to represent and manipulate numbers—fingers, tallies, tokens, and written notations— the mechanism for their elaboration and the source of their various properties. With this model, cross-cultural variability becomes a simple matter of whether material devices are used, which devices are used, and how those devices are used." The "technological layering of material forms systematized by device affordances and limitations that predictably and reliably emerge from the interaction of numerosity, material form, behaviors, and social needs." This research has been highlighted as "a naturalistically plausible account of the emergence of the modern natural number concept" and "a 'Copernican Revolution' in the way we understand the relationship between numbers and the material devices we use to record and manipulate them."She has analyzed counting artifacts from the Ancient Near East, including fingers, tallies, tokens, and notations. She later expanded the catalogue of Near Eastern tokens published by Denise Schmandt-Besserat in 1992 with over 2,300 new entries. The results of analyzing the updated token catalogue were published in 2019 as a component of Overmann's book, The Material Origin of Numbers.
Overmann has also investigated the traditional counting methods used in Oceania, particularly Polynesia; this research solved two mysteries of several centuries' standing: what was meant by the claim that Māori counted by "elevens" and why the Hawaiian word for twenty, iwakalua, meant "nine and two"; both are related to the method of counting by sorting used in Polynesia. She coined the term "ephemeral abacus" to refer to temporary material forms with inherent place value, including collaborative finger-counting and counting by sorting. In 2021, she published a detailed comparison of Polynesian and Mesopotamian numbers, both of which use object-specified counting sequences; the more recent counting practices of Polynesia provide a new way to understand how such counting would have worked in ancient times.