Settlement size predicts extreme variation in the rates and magnitudes of many social and ecological processes in human societies. Yet, the factors that drive human settlement-size variation remain poorly understood. Size variation among economically integrated settlements tends to be heavy tailed such that the smallest settlements are extremely common and the largest settlements extremely large and rare. The upper tail of this size distribution is often formalized mathematically as a power-law function. Explanations for this scaling structure in human settlement systems tend to emphasize complex socioeconomic processes including agriculture, manufacturing, and warfare-behaviors that tend to differentially nucleate and disperse populations hierarchically among settlements. But, the degree to which heavy-tailed settlement-size variation requires such complex behaviors remains unclear. By examining the settlement patterns of eight prehistoric New World hunter-gatherer settlement systems spanning three distinct environmental contexts, this analysis explores the degree to which heavy-tailed settlement-size scaling depends on the aforementioned socioeconomic complexities. Surprisingly, the analysis finds that power-law models offer plausible and parsimonious statistical descriptions of prehistoric hunter-gatherer settlement-size variation. This finding reveals that incipient forms of hierarchical settlement structure may have preceded socioeconomic complexity in human societies and points to a need for additional research to explicate how mobile foragers came to exhibit settlement patterns that are more commonly associated with hierarchical organization. We propose that hunter-gatherer mobility with preferential attachment to previously occupied locations may account for the observed structure in site-size variation.

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Notes/Citation Information

Published in PLOS One, v. 10, no. 11, article e0140127, p. 1-25.

© 2015 Haas et al.

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

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Funding Information

This study was supported by the National Science Foundation BCS-0331992 awarded to Haas, American Philosophical Society Lewis and Clark Fund awarded to Haas, National Science Foundation BCS-9816313 awarded to Aldenderfer, Wenner Gren Foundation 6174 awarded to Klink, and National Science Foundation BCS-0331992 awarded to Maggard. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

journal.pone.0140127.s001.CSV (44 kB)
S1 Specimens. Archaeological specimens.

journal.pone.0140127.s002.TXT (5 kB)
S1 Dataset. Artifact count and site area data.

journal.pone.0140127.s003.ZIP (3390 kB)
S1 Code. R code used to analyze data.

journal.pone.0140127.s004.PDF (27 kB)
S1 Table. Numerical results of power analysis for artifact-count data.

journal.pone.0140127.s005.PDF (28 kB)
S2 Table. Numerical results of power analysis for site-area data.

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