Population size predicts technological complexity in Oceania

Abstract

Much human adaptation depends on the gradual accumulation of culturally transmitted knowledge and technology. Recent models of this process predict that large, well-connected populations will have more diverse and complex tool kits than small, isolated populations. While several examples of the loss of technology in small populations are consistent with this prediction, it found no support in two systematic quantitative tests. Both studies were based on data from continental populations in which contact rates were not available, and therefore these studies do not provide a test of the models. Here, we show that in Oceania, around the time of early European contact, islands with small populations had less complicated marine foraging technology. This finding suggests that explanations of existing cultural variation based on optimality models alone are incomplete because demography plays an important role in generating cumulative cultural adaptation. It also indicates that hominin populations with similar cognitive abilities may leave very different archaeological records, a conclusion that has important implications for our understanding of the origin of anatomically modern humans and their evolved psychology.

Figure 1.

Number of tools as a function of population size. Larger populations have significantly more tool types than smaller populations. The trend line is based on a linear regression of the logarithm of the number of tools against the logarithm of population size (β = 0.805, p = 0.005, n = 10). Four of five low-contact groups have fewer tools than expected, whereas four out of five high-contact groups exceed the expected number of tools. Diamonds, low contact; triangles, high contact.

Figure 2.

Mean number of techno-units by population size. Larger populations have significantly more complex tools than smaller populations. The trend line is based on a linear regression of the logarithm of mean techno-units per tool against the logarithm of population size (β = 0.706, p = 0.022, n = 10). Diamonds, low contact; triangles, high contact.