Archeologists have long used the shapes and styles of pottery as a proxy for ancient cultures. But how does the cultural alignment of ceramic forms arise? To explore this question, Tetsushi Nonaka and colleagues asked 21 potters in three different communities—one in France in Bourgogne and two in India in Bulandshahar district, Uttar Pradesh—to throw pots with the same unfamiliar shapes.

One of the Indian pottery workshops was Hindu, the other was Muslim. In each community, several different potters tried the shapes. Through careful measurement, the authors were able to determine that there was more variation between communities that between potters within the same community. The process of making pots was filmed, and so the authors were also able to determine that the morphogenic path of pots was also more different between communities than within communities.

For example, Hindu Prajapati potters tended to take their shapes higher than the final form before bringing the clay back down, while Muslim Multani Kumhar potters tended to gradually approach the final height without much exceeding it. French potters began their vases with a flat disc, a choice that tended to result in final products with wider bases.

Overall, community-specific deviations of morphological features of vessels support the common assumption that pots with similar shapes are made by the same community. However, individual potters also had their own idiosyncratic styles, a finding that should encourage archeologists to consider individual variation in their theories of cultural evolution, according to the authors.