"Japanese Roots"

by Jared Diamond / From Discover

Unearthing the origins of the Japanese is a much harder task than you might guess. Among world powers today, the Japanese are the most distinctive in their culture and environment. The origins of their language are one of the most disputed questions of linguistics. These questions are central to the self-image of the Japanese and to how they are viewed by other peoples. Japan’s rising dominance and touchy relations with its neighbors make it more important than ever to strip away myths and find answers.

The search for answers is difficult because the evidence is so conflicting. On the one hand, the Japanese people are biologically undistinctive, being very similar in appearance and genes to other East Asians, especially to Koreans. As the Japanese like to stress, they are culturally and biologically rather homogeneous, with the exception of a distinctive people called the Ainu on Japan’s northernmost island of Hokkaido. Taken together, these facts seem to suggest that the Japanese reached Japan only recently from the Asian mainland, too recently to have evolved differences from their mainland cousins, and displaced the Ainu, who represent the original inhabitants. But if that were true, you might expect the Japanese language to show close affinities to some mainland language, just as English is obviously closely related to other Germanic languages (because Anglo-Saxons from the continent conquered England as recently as the sixth century a.d.). How can we resolve this contradiction between Japan’s presumably ancient language and the evidence for recent origins?

Archeologists have proposed four conflicting theories. Most popular in Japan is the view that the Japanese gradually evolved from ancient Ice Age people who occupied Japan long before 20,000 b.c. Also widespread in Japan is a theory that the Japanese descended from horse-riding Asian nomads who passed through Korea to conquer Japan in the fourth century, but who were themselves—emphatically—not Koreans. A theory favored by many Western archeologists and Koreans, and unpopular in some circles in Japan, is that the Japanese are descendants of immigrants from Korea who arrived with rice-paddy agriculture around 400 b.c. Finally, the fourth theory holds that the peoples named in the other three theories could have mixed to form the modern Japanese.

When similar questions of origins arise about other peoples, they can be discussed dispassionately. That is not so for the Japanese. Until 1946, Japanese schools taught a myth of history based on the earliest recorded Japanese chronicles, which were written in the eighth century. They describe how the sun goddess Amaterasu, born from the left eye of the creator god Izanagi, sent her grandson Ninigi to Earth on the Japanese island of Kyushu to wed an earthly deity. Ninigi’s great-grandson Jimmu, aided by a dazzling sacred bird that rendered his enemies helpless, became the first emperor of Japan in 660 b.c. To fill the gap between 660 b.c. and the earliest historically documented Japanese monarchs, the chronicles invented 13 other equally fictitious emperors. Before the end of World War II, when Emperor Hirohito finally announced that he was not of divine descent, Japanese archeologists and historians had to make their interpretations conform to this chronicle account...

Why do they care so much? Unlike most other non-European countries, Japan preserved its independence and culture while emerging from isolation to create an industrialized society in the late nineteenth century. It was a remarkable achievement. Now the Japanese people are understandably concerned about maintaining their traditions in the face of massive Western cultural influences. They want to believe that their distinctive language and culture required uniquely complex developmental processes. To acknowledge a relationship of the Japanese language to any other language seems to constitute a surrender of cultural identity.

What makes it especially difficult to discuss Japanese archeology dispassionately is that Japanese interpretations of the past affect present behavior. Who among East Asian peoples brought culture to whom? Who has historical claims to whose land? These are not just academic questions. For instance, there is much archeological evidence that people and material objects passed between Japan and Korea in the period a.d. 300 to 700. Japanese interpret this to mean that Japan conquered Korea and brought Korean slaves and artisans to Japan; Koreans believe instead that Korea conquered Japan and that the founders of the Japanese imperial family were Korean...

Since languages change over time, the more similar two languages are, the more recently they must have diverged. By counting common words and features, linguists can estimate how long ago languages diverged, and such estimates suggest that Japanese and Korean parted company at least 4,000 years ago. As for the Ainu language, its origins are thoroughly in doubt; it may not have any special relationship to Japanese....

The seas that surround much of Japan and coastal East Asia are shallow enough to have been dry land during the ice ages, when much of the ocean water was locked up in glaciers and sea level lay at about 500 feet below its present measurement. Land bridges connected Japan’s main islands to one another, to the Russian mainland, and to South Korea. The mammals walking out to Japan included not only the ancestors of modern Japan’s bears and monkeys but also ancient humans, long before boats had been invented. Stone tools indicate human arrival as early as half a million years ago.

Around 13,000 years ago, as glaciers melted rapidly all over the world, conditions in Japan changed spectacularly for the better, as far as humans were concerned. Temperature, rainfall, and humidity all increased, raising plant productivity to present high levels. Deciduous leafy forests full of nut trees, which had been confined to southern Japan during the ice ages, expanded northward at the expense of coniferous forest, thereby replacing a forest type that had been rather sterile for humans with a much more productive one. The rise in sea level severed the land bridges, converted Japan from a piece of the Asian continent to a big archipelago, turned what had been a plain into rich shallow seas, and created thousands of miles of productive new coastline with innumerable islands, bays, tidal flats, and estuaries, all teeming with seafood...

Despite its distinctiveness even in East Asia at that time, Jomon Japan was not completely isolated. Pottery, obsidian, and fishhooks testify to some Jomon trade with Korea, Russia, and Okinawa—as does the arrival of Asian mainland crops. Compared with later eras, though, that limited trade with the outside world had little influence on Jomon society. Jomon Japan was a miniature conservative universe that changed surprisingly little over 10,000 years...

More than 10,000 years after the invention of pottery and the subsequent Jomon population explosion, a second decisive event in Japanese history triggered a second population explosion. Around 400 b.c., a new lifestyle arrived from South Korea. This second transition poses in acute form our question about who the Japanese are. Does the transition mark the replacement of Jomon people with immigrants from Korea, ancestral to the modern Japanese? Or did Japan’s original Jomon inhabitants continue to occupy Japan while learning valuable new tricks?

The new mode of living appeared first on the north coast of Japan’s southwesternmost island, Kyushu, just across the Korea Strait from South Korea. There we find Japan’s first metal tools, of iron, and Japan’s first undisputed full-scale agriculture. That agriculture came in the form of irrigated rice fields, complete with canals, dams, banks, paddies, and rice residues revealed by archeological excavations. Archeologists term the new way of living Yayoi, after a district of Tokyo where in 1884 its characteristic pottery was first recognized. Unlike Jomon pottery, Yayoi pottery was very similar to contemporary South Korean pottery in shape. Many other elements of the new Yayoi culture were unmistakably Korean and previously foreign to Japan, including bronze objects, weaving, glass beads, and styles of tools and houses...

It took several centuries for Yayoi Japan to show the first signs of social stratification, as reflected especially in cemeteries. After about 100 b.c., separate parts of cemeteries were set aside for the graves of what was evidently an emerging elite class, marked by luxury goods imported from China, such as beautiful jade objects and bronze mirrors. As the Yayoi population explosion continued, and as all the best swamps or irrigable plains suitable for wet rice agriculture began to fill up, the archeological evidence suggests that war became more and more frequent: that evidence includes mass production of arrowheads, defensive moats surrounding villages, and buried skeletons pierced by projectile points. These hallmarks of war in Yayoi Japan corroborate the earliest accounts of Japan in Chinese chronicles, which describe the land of Wa and its hundred little political units fighting one another...

Measurements have now been made of many skeletons. In addition, within the last three years molecular geneticists have begun to extract dna from ancient human skeletons and compare the genes of Japan’s ancient and modern populations. Jomon and Yayoi skeletons, researchers find, are on the average readily distinguishable. Jomon people tended to be shorter, with relatively longer forearms and lower legs, more wide-set eyes, shorter and wider faces, and much more pronounced facial topography, with strikingly raised browridges, noses, and nose bridges. Yayoi people averaged an inch or two taller, with close-set eyes, high and narrow faces, and flat browridges and noses. Some skeletons of the Yayoi period were still Jomon-like in appearance, but that is to be expected by almost any theory of the Jomon-Yayoi transition. By the time of the kofun period, all Japanese skeletons except those of the Ainu form a homogeneous group, resembling modern Japanese and Koreans.

In all these respects, Jomon skulls differ from those of modern Japanese and are most similar to those of modern Ainu, while Yayoi skulls most resemble those of modern Japanese. Similarly, geneticists attempting to calculate the relative contributions of Korean-like Yayoi genes and Ainu-like Jomon genes to the modern Japanese gene pool have concluded that the Yayoi contribution was generally dominant. Thus, immigrants from Korea really did make a big contribution to the modern Japanese, though we cannot yet say whether that was because of massive immigration or else modest immigration amplified by a high rate of population increase. Genetic studies of the past three years have also at last resolved the controversy about the origins of the Ainu: they are the descendants of Japan’s ancient Jomon inhabitants, mixed with Korean genes of Yayoi colonists and of the modern Japanese...


That is, the modern Ainu language of Hokkaido is not a model for the ancient Jomon language of Kyushu. By the same token, modern Korean may be a poor model for the ancient Yayoi language of Korean immigrants in 400 b.c. In the centuries before Korea became unified politically in a.d. 676, it consisted of three kingdoms. Modern Korean is derived from the language of the kingdom of Silla, the kingdom that emerged triumphant and unified Korea, but Silla was not the kingdom that had close contact with Japan in the preceding centuries. Early Korean chronicles tell us that the different kingdoms had different languages. While the languages of the kingdoms defeated by Silla are poorly known, the few preserved words of one of those kingdoms, Koguryo, are much more similar to the corresponding Old Japanese words than are the corresponding modern Korean words. Korean languages may have been even more diverse in 400 b.c., before political unification had reached the stage of three kingdoms. The Korean language that reached Japan in 400 b.c., and that evolved into modern Japanese, I suspect, was quite different from the Silla language that evolved into modern Korean. Hence we should not be surprised that modern Japanese and Korean people resemble each other far more in their appearance and genes than in their languages.

History gives the Japanese and the Koreans ample grounds for mutual distrust and contempt, so any conclusion confirming their close relationship is likely to be unpopular among both peoples. Like Arabs and Jews, Koreans and Japanese are joined by blood yet locked in traditional enmity. But enmity is mutually destructive, in East Asia as in the Middle East. As reluctant as Japanese and Koreans are to admit it, they are like twin brothers who shared their formative years. The political future of East Asia depends in large part on their success in rediscovering those ancient bonds between them.