Figure 5. Country norms of language size. Darker shades indicate a tendency to smaller
languages, lighter shades indicate a tendency to larger languages.
Figure 6 presents the global distribution of the linguistic diversity index of
Paolillo (2005). Higher values of diversity mean either larger numbers of languages
and/or a more even distribution of language sizes. This can be seen to be somewhat
complementary to the distribution of language sizes in Figure X, although there are some
differences. First, it becomes immediately evident that Papua New Guinea is the country
with the greatest linguistic diversity. Europe, Northern Africa and Western Asia, the
region of numerous empires over several millennia, has probably the greatest
concentration of countries low in linguistic diversity. The many rapid successive
expansions of peoples across these areas has left mostly large and few smaller languages.
Europe is the home of the Indo-European family, which has more large languages than
any other language family. Northern Africa and Western Asia are dominated by the Afro-
Asiatic family, most notably Arabic, whose spread throughout the region is somewhat
more recent than the Indo-European languages. Other areas with notably low diversity
are Japan, the Koreas, New Zealand, Uruguay, Argentina and Chile. Some of these
countries experienced political unification in the late 19
th
and early 20
th
centuries, in
which imposition of a standard language played an important role.
Countries showing relatively high linguistic diversity, such as Indonesia,
Malaysia, India, the Democratic Republic of the Congo, Nigeria, Cameroon and Mexico
have somewhat different histories. While the expansion of Austronesian language
speakers into Indonesia, Malaysia and New Zealand was relatively recent, the cultural
patterns of these people did not manifest in the form of large empires. Political
unification of New Zealand, or the Hawaiian Islands did not take place until after the
arrival of European mercantile traders, whose military technology and domesticated food
plants catalyzed these political developments (Diamond 1997).
Figure 6. Linguistic diversity. Lighter colors indicate greater linguistic diversity.
Using the log-linear model, it is possible to investigate the independent
contributions of linguistic family and country to the linguistic diversity observed in
Figure 6, through partitioning the variance of the model into those two components. The
effect of linguistic family represents the contribution of population expansion. Rapidly
population expansion tends to result in larger language groups and lower diversity. When
language groups attain a certain size, they becomes more likely to split into smaller,
daughter languages, but for as long as circumstances facilitate the movement and
communication among people, languages can expand as well. By locating diversity of
within language families by country, one can identify regions where expansion has been
most rapid (low diversity) or where more splitting has taken place (the ancestral
homeland of a language family or families). Similarly, the effect of country represents the
geographic contribution limiting the movements of people groups and splitting them into
non-communicating groups, or conversely facilitating the movement of people and
communication with relatively open terrain.
Figure 7 locates the language family component of diversity. Notably, China,
Mexico and Indonesia, locations of three historic population expansions (Diamond 1997,
2005) have quite low levels of family diversity. In China, agricultural innovations several
millennia ago, and favorable terrain for its exploitation have steadily propelled the
region’s population to the point where Mandarin Chinese is the single largest language
spoken today. In Mexico, similar innovations were responsible for the Mayan and Aztec
empires, although the more recent expansion of Indo-European Spanish probably has a
heavy imprint. And Indonesia is the main domain of the Austronesian expansion,
propelled literally by innovations in nautical navigation. All countries are dominated by a
few language families with many linguistically similar and relatively larger languages.
Figure 7. Linguistic diversity, family component. Lighter colors indicate greater
linguistic diversity accounted for by language family.
As we have noted before, some elements are apparently missing from this picture,
and this points to a need to review the organization and classification of the Ethnologue
data more thoroughly. For example, the United States has a relatively low linguistic
diversity, is the domain of the recent expansion of Indo-European languages (English,
Spanish, French and others), but it appears to show a median level of linguistic diversity.
It is not immediately apparent why the United States should be different in this respect
from Mexico. Similar arguments could be made for Canada. The possibility that the
inclusion of extinct languages, or the exclusion of Immigrant languages is responsible for
this anomaly underscores the need for a comprehensive review of the Ethnologue
population data.