Javanese influence on Japanese

In the previous posting, I discussed the issue of the (pre)historic Japanese homeland. Scholars of Japanese prehistory typically distinguish two cultures that merged to create the Japanese culture as we know it: the earlier Jōmon culture and the later Yayoi culture. The question is where these cultures/peoples came from? As discussed in the previous posting, linguistic evidence suggests that one of the groups came from Korea and brought with it (influences of) an Altaic language, whereas the other group is Austronesian in origin and came from Taiwan or some other place where an Austronesian language is spoken.

But which of the two prehistoric Japanese cultures came from where? According to the more widely-accepted hypothesis (assumed also by Lee and Hasegawa), the Jōmon people are Austronesians and the Yayoi people are Altaic (Korean). But this is not the only hypothesis out there.

Quite a converse view is defended by Ann Kumar in her Globalizing the Prehistory of Japan: Language, Genes and Civilization (Routledge, 2009). She puts together an argument from linguistics, genetics, physical anthropology and comparative mythology for a pivotal late prehistoric migration from Java to Japan. Kumar makes claims of an immigration of elites from the island of Java in Indonesia which brought hierarchical society to Japan, with rice and key myths of origin and power, as well as traditions of metalurgy and theatre. Crucially, for Kumar it is the Yayoi culture that came from Austronesian speaking lands, not the Jōmon culture.

One archeological argument for her theory relies on the claim that "there have actually been no prehistoric paddy fields yet escavated in China" (p. 29), or in Korea for that matter. However, there is good evidence that rice was domesticated in the fifth millenium BCE in the Yangtze, with rice fields making appearance in the Shandong peninsula just west of Korea as early as the third millenium BCE. Plant genetics must be further invoked in order to sort out the relationship of the Japanese japonica rice and the Javanese javanica rice, as well as the domestication history of other relevant plants, including barnyard millet, azuki bean and Cannabis. Human genetics evidence too seems to provide some support to Kumar's claims but also raises some problems for her theory: it appears that, all in all, the more ancient genetic lineages in Japan share their ancestry with Central Asian, Northwest Chinese and Tibetans, whereas genetic affinities between Japan, Southeast China and Southeast Asia are found in younger lineages.

Finally, in chapter 6 of her book, Kumar provides some linguistic evidence for Javanese influence on (Old) Japanese. However, she does not claim that Japanese is an Austronesian language, deriving from some form of proto-Javanese. Instead, she maintains that the precursor of Javanese provided a superstratum language that affected the precursor of (Old) Japanese. This is indeed what we would expect if the Javanese influence on Japanese results from an immigration of elites rather than mass settlement, just as was the case with the Vikings making large lexical contributions to the English language or the Turkic speakers making a similar contribution to the Russian language. In her book, Kumar identifies 82 plausible Javanese-Japanese cognates and points out that many of them involve such areas as rice cultivation.

While many of Kumar's arguments are worthy of further consideration, there are numerous problems with her factual material and with the interpretation of some of the facts (both linguistic and genetic). So the prehistory of Japan will remain a mystery for a while longer.