A global cross-cultural analysis of string figures reveals evidence of deep transmission and innovation

Abstract

Few cultural practices beyond language are as widespread as string figure games. Their global distribution and potential to yield insights into cultural transmission and cognition have long been noted. Yet, it remains unknown how or when this behaviour originated and to what extent shared motifs are signals of repeated innovations or deep cultural transmission. Here, we combined a global cross-cultural inventory of string figures with a novel methodology based on knot theory, which enables the unequivocal numerical coding of string figures. We performed a computational analysis of a sample of 826 figures from 92 societies around the world. Across these societies, we found 83 recurring string figure designs, some of which are regionally restricted while others display a global distribution. The cognitively opaque nature of string figure designs and their clear geographic distribution reveal processes of cultural transmission, innovation, and convergent evolution. Most strikingly, the global distribution of some figures raises the possibility of shared ancient origins.

Keywords: cognition; cognitive anthropology; cultural evolution; cultural transmission; ethnomathematics; knot theory.

Figure 1.

Six string figures with varying structural features and geographical distributions. Jacob’s ladder: one of the most widespread string figures (electronic supplementary material, 3). Takapau: a symmetrical string figure widely distributed in Oceania (electronic supplementary material, 3). Hare: an animated string figure common across the Arctic, representing a hare or caribou. The figure can be set to move as if it runs from right to left; it disappears when it reaches the left end. Many stars: a figure exclusive to western North America. Swan: a complex asymmetrical animal-form string figure documented among the Copper Inuit. Exemplary of Arctic string figure traditions, the Swan is associated with a story: the swan resolves into a loop when the maker releases it, representing a swan leaving its lake behind. Na Ubwebwe: a simple four-diamond motif, and perhaps the most widespread string figure structure in Oceania. Although it is made with various methods (electronic supplementary material, 3), its structure is practically exclusive to the Oceanic region. A map illustrating the geographical distribution of each of the six string figures in our dataset.

Figure 2.

Cultures represented in our dataset. Coordinates are based on data from glottolog [48]. Cultures included in the standard cross-cultural sample (SCCS) are coloured blue, and other cultures are coloured red. The shapes of the pins vary by traditional subsistence strategy, illustrating how societies with variable economies have made string figures.

Figure 3.

Dendrogram of the global string figure sample. Figure 3 is also available as a high-definition text-searchable PDF in the electronic supplementary material (figure S1) [49]. Individual string figures appear at the tips of the tree and are coloured by the geographical region (refer to the world map in the centre for colours). Higher order clusters group increasingly diverse figure designs. Clusters at the outermost edge of the tree contain identical or near-identical string figures. Clusters described in electronic supplementary material, table 1, are numbered and connected with a crossbar at the tip (the cluster numbers refer to the respective section in electronic supplementary material, table 1). Likewise, clusters close to each other (under the same branch) contain structurally similar string figures.

Figure 4.

Analysis of the geographical distribution of structurally identical (a) and non-identical (b) string figure pairs. Histogram (a) (blue) depicts the geographical distribution of structurally identical string figures. Histogram (b) (grey) depicts the geographical distribution of non-identical (i.e. all other) pairs of string figures. Plot (c) overlays the smoothed density distributions of histograms (a,b) allowing the comparison of the geographical distribution of identical and non-identical string figures. Within-culture comparisons are excluded from this figure.

Figure 5.

Net-like diamond patterns are common themes in prehistoric art. Some net-like patterns resemble common string figure structures. Although this does not indicate that these prehistoric patterns represent string figures, they do demonstrate the ancient human visual appeal for such motifs. Left: Ochre stone art found at the Blombos Cave site, South Africa (ca 70 000 BP) (Wikimedia Commons, by Chris S. Henshilwood, CC-BY-SA−4.0). Right: A string figure of the Polynesian Turtle shell class.