The shape of shared attention: Investigating the influence of environmental variation on the compositional structure of traditional decorative artworks.

Styles of traditional decorative art vary substantially across cultures. While early theorists attributed this variation to differences in environment, scholarship has long focused on decorative artworks as vehicles of social information and stylistic variation as a consequence of social factors. However, if the capacity to create and consume art evolved as a mechanism to shape shared attention, it is possible that environmental factors may indeed play a role in variation of decorative style. We tested this hypothesis by characterizing the compositional structure of 198 textiles from eighteen cultures across the globe using the complexity-entropy plane. Entropy and statistical complexity have previously been used to characterize changes in the compositional structure of paintings of the Western canon over the last millennium. We observed that complexity and entropy are useful measures for characterizing traditional textile designs: high-entropy/low-complexity samples feature dense repetitions of small Euclidean shapes, while low-entropy/high-complexity samples feature large, single-color fields with bold borders. We observed weak-but-significant associations between these measures and three environmental variables: absolute latitude, Koppen climate classification, and a composite variable representing subsistence mode. Interestingly, we observed a significant difference between works from Afro-Eurasia/Oceania and the Americas. Controlling for this and other factors related to social transmission improves the strength of the relationship between compositional structure and subsistence mode. We propose that aesthetic preferences may be affected by subsistence mode as well as cultural factors, and suggest that further studies with more granular environmental data are necessary. We further discuss potential explanations for the observed difference between "hemispheres."