This published version of Adam Rorabaugh's dissertation at Washington State University ambitiously addresses social dynamics in precontact Coast Salish communities in northwestern North America using projectile-point data. Specifically, Rorabaugh argues that technical knowledge for the manufacture and maintenance of “hafted” stone tools (knives and projectile points but mainly projectile points) became increasingly restricted among elites along the Pacific Northwest coast over the last five millennia. This model of change in patterns of cultural transmission over time is supported by Rorabaugh's assessment of stylistic and metric variation in flaked and ground stone projectile points.

The book includes an excellent summary of the emergence of hereditary social inequality and how it is theorized to have evolved with restricted learning in the Salish Sea, a marine embayment along the Pacific coasts of Washington State and British Columbia. The shorelines and islands of the Salish Sea correspond to the historical distribution of Indigenous Coast Salish speakers well known for their rich artistic and cultural traditions. Great wealth and political power accrued to leaders of Coast Salish communities and led to economic and social inequality.

Although not its main thrust, the book reduces the complex and myriad technologies of the region to a chronological function in archaeology—that is, the technologies are equated to projectile-point types that are thought to characterize specific periods, such as index fossils in paleontology. Rorabaugh does offer two production sequences generically describing raw material selection, manufacturing techniques, and maintenance. One sequence describes ground stone knives and projectile points, and another sequence describes flaked stone knives and projectile points. This nod to behavioral approaches in lithic technology appears to be a point of departure for arguing that maintenance retouch (resharpening and repair) primarily affects the distal end and lateral margins of projectile points, whereas the proximal end (haft element) is generally unaltered during its use life. Because the haft element exhibits most of the variation used in projectile-point typology, its purported stability during use life is critical to projectile-point chronology and is a weak link in the argument. Rorabaugh rightfully suggests that experimentation could be used to test the idea of haft-element use-life stability of projectile points.

Rorabaugh demonstrates excellent command of the literature on evolutionary theory and its application to archaeology. Unfortunately, this evolutionary approach often emphasizes arbitrary quantitative measures of variability over qualitative and functional analyses. In the current study, this leads to the poorly supported assertion that all haft-element variation is “equally performing” and therefore stylistic, serving to communicate cultural information to those with appropriate cultural knowledge. However, haft-element variability is largely hidden by wraps and mastics when projectile points are actually hafted onto spears, darts, and arrows, so cultural signaling is masked. Furthermore, projectile-point haft elements serve several different functions in addition to securing the point to the shaft. These additional haft-element functions include controlling impact breakage to the projectile point through designs that make it more durable or repairable, and retention of the point in the wound through designs that create barbs. Haft-element variation is not equally performing for these functions.

Rorabaugh's forte is statistical analysis, and he uses it to test the hypothesis that restricted learning results in low stylistic richness and evenness as well as low variation in measurements of projectile points. The book describes methods of harvesting data from existing publications and museum collections, and it presents the results of statistical analyses of projectile-point type frequencies and metric variability. It considers factors such as lithic raw material quality and the transition from dart-and-atlatl technology to bow-and-arrow technology in assessing variability by subregion within the Salish Sea as well as by time period. The results show stylistic evenness (but not richness), and metric variation corresponds to expectations for more restricted knowledge during the later periods.

Rorabaugh provides an in-depth discussion of critiques of cultural transmission studies and addresses key problems of sample-size effects, refurbishment of projectile points, material quality, and adoption of bow-and-arrow technology. Rorabaugh also discusses diachronic technological changes, including reduction in projectile-point size, introduction of stemmed haft elements, and transition from lanceolate to triangular projectile point outline forms. He also suggests a regional stylistic or symbolic grammar in projectile point technologies based on uniformity throughout the Salish Sea.

I am not convinced that projectile-point change over time, by itself, is a good indicator of changes in modes of technical knowledge transmission and its implications for the structure of society. However, Rorabaugh has contributed important ideas about lithic technology and its relationship to the evolution of late Holocene society of the Salish Sea.