Bayes versus Pragmatism: A Debate about Dating Hawaiian Temples

Article excerpt

Hawaiian temples and Bayesian chronology

[T]he chronological development of the Kohala, Kona, Waimea, Kahikinui, and Kalaupapa field systems, spanning three islands, is remarkably congruent. While there was some low intensity land use in Kohala and Kona prior to AD 1400, in all cases the onset of major dryland cultivation began around AD 1400. Following about two centuries of development, a final phase of intensification, typically marked by highly formalized garden plots and territorial boundaries, commenced about AD 1600 to 1650, and continued until the early post-contact period. Unlike the irrigation systems, many of which have continued in use throughout the nineteenth and twentieth centuries, the dryland field systems were all rapidly abandoned within a few decades following European contact (Kirch 2010:153).

This chronology is adopted in a recent paper by McCoy et al. (2011: 939) as a 'ruling theory' (Chamberlin 1965), part of a larger argument that links field system development with the rise of elite authority, leading to what the authors refer to as the political elite "completely subsuming religious authority". The chronology the authors derive from their material stretches back to the late fifteenth century, which puts it in broad conformity with the ruling theory.

The centerpiece of their paper is a seriation of religious temples in the Leeward Kohala Field System (LKFS) that purports to arrange their construction dates in time. Hawaiian religious temples are famously variable and more than one attempt to order them formally has come to nothing (Bennett 1930; Stokes 1991). One reason for the formal variability was discovered when Kane'aki Heiau on O'ahu was excavated and shown to have been remodelled, often substantially, several times during its history (Ladd 1973). Hawaiian tradition is clear that remodelling temples was a common practice (Malo 1996: 82, 241). Features that the authors used to seriate the LKFS temples, and that presumably inform on the construction date, were shown at Kane'ald Heiau to be architectural components that might be added during a later remodelling stage. Because the seriation method for single objects dates "the time at which the attributes came together to make up the object" (Dunnell 1970: 307), the seriation proposed by the authors might track a history of remodelling events, rather than a history of construction.

This potential decoupling of the seriation from construction events is important because the authors use the seriation results to accept radiocarbon dates from beneath seven temples and to reject dates from beneath four others. This step is unfortunate because the radiocarbon dates were collected in a way that established their stratigraphic relationship beneath the basal stones of structures, a practice frequently ignored in Hawaiian archaeology. Care was taken to date short-lived woods selected from confidently identified charcoal to control for the effects of old wood. This careful procedure establishes the stratigraphic boundaries of two periods, one under the structure that pre-dates construction and another above the basal stones that post-dates construction. If the start and end dates of these periods are designated [alpha] and [beta], respectively, then the dating model can be expressed as [[alpha].sub.pre] > [[beta].sub.pre] = [[alpha]] > [[beta]] = AD 1819, where the symbol > is taken to mean 'is older than.' In plain English, this model says that the pre-construction period began at some unknown point in the past and ended when the post-construction period began, and that the post-construction period lasted until the overthrow of the traditional religion in AD 1819.

This model makes clear that the best estimate of the construction date, [[alpha]], is the end of the pre-construction period, or [[beta].sub.pre]. The authors instead use an approximation of [[alpha].sub.pre] as the terminus post quem for the construction date. …