Blute Blog

The piece with which I began this blog on March 4^th was about the application of phylogenetic methods derived from Biology to sociocultural topics. That work has now been extended to political evolution and the article by Currie, Greenhill, Gray, Hasegawa and Mace (gated) with a commentary by Jared Diamond made the cover of Nature on October 14(V467, 801-4 & 798-9 gated). (Nature now categorizes its “news & views” i.e. commentaries and its “letters” i.e. research articles by subject, and interestingly, they have categorized this article as “evolution” and Diamond’s commentary on it as “sociology”. So much for disciplinary labels! Perhaps the authors get to choose?)

The topic is again the peopling of island South-East Asia and the Pacific by speakers of Austronesian languages beginning from modern day Taiwan about 3200 BC. The authors mapped forms of political organization (acephalous, simple chiefdom, complex chiefdom or state) onto the tips of a language tree of 84 Austronesian societies and used state of the art phylogenetic methods (described in supplementary materials) to test models of their political evolution. Diamond praises the superiority of the methods used over more traditional narrative accounts (including his own) and usefully summarizes the results as follows:

“First, political evolution increases only in small steps: states and complex chiefdoms don’t form directly from leaderless societies. This conclusion fits historical observations of the formation of complex societies (for instance, the Malagasy, Cherokee and Zulu states), when one unit at the next-lower level succeeded in conquering or incorporating its neighbours. Second, political complexity can decrease as well as increase, in agreement with abundant evidence of the disintegration of states and chiefdoms. Finally, unlike increases of complexity, declines can plunge a society politically several stages backwards. This can happen if a small group breaks off from a large society to form a small new society (as in the colonization of the Chatham Islands from New Zealand), or if political institutions disintegrate (as on Mangareva in Polynesia).”

By contrast, in another recent article on political evolution based on more traditional materials, Abrutyn and Lawrence (gated) argue that gradual quantitative change in sociocultural evolution can reach thresholds where qualitative punctuated change ensues. “Punctuated equilibrium . . . has more empirical support than gradualism in explaining state formation.” In Mesopotamia and Egypt for example states emerged where chiefdoms did not exist.

Obviously we have not yet heard the last word on political evolution.