Atkinson on phoneme inventories in Science

[Johanna Nichols]

This is written up to be more or less self-standing, but please DON'T
QUOTE it without asking me first -- I'm expanding the sample for this and
there will be changes.

Johanna


Atkinson 2011 finds a significant positive correlation between population
size and phoneme inventory size (confirming Hay & Bauer 2007) and explains
it by migration:  phoneme sizes are largest in Africa, and as societies
spread out of Africa and around the world they went through population and
cultural bottlenecks and underwent phonological simplification as a
consequence.  I believe the correlation is artifactual.

As background, Sproat 2011 points out that Atkinson's language sizes range
from a few tens of speakers to hundreds of millions of speakers.  But
population sizes in the Paleolithic were small, probably at most a few
thousand speakers and often fewer.  If Atkinson's explanation is correct,
the positive correlation between population size and phoneme inventory
size should also hold among just the smaller population sizes; looking at
Fig. S1, there does still seem to be a positive correlation, but it looks
considerably weaker.  I agree with Sproat on all these points.

In Nichols 2009, a cross-linguistic survey of overall grammatical
complexity, I found a highly significant negative correlation between
overall complexity and population size:  smaller communities have more
complex languages.  But that proves to be an artifact of the larger
population sizes and lower structural complexity in Africa and Eurasia: 
within subglobal areas (Old World, Pacific, New World) there is no
correlation.  The large language-population sizes in Africa and Eurasia
have to do with the long history of statehood and empire (which spread big
state languages at the expense of smaller ones), economic growth, and
efficient food production (themselves accidents of geography: Diamond
1997).  Also, European colonization brought smallpox and economic
destruction to the Americas and Australia, drastically reducing
populations, and the population figures we have are post-colonial.  Big
trade languages, state languages, and other inter-ethnic languages tend to
be simpler than small ethnic languages (Trudgill 2009, Szmrecsanyi &
Kortmann 2009, Dahl 2004), and there have been many more of these in
Africa and Eurasia than in the pre-contact Americas and Pacific.

So, does Atkinson's positive correlation in phonology hold within large
areas as well as worldwide?  I took the data on phonological complexity
from my 2009 paper, quickly surveyed a few more languages to fill gaps,
and did some counts.  Now, my data measures phonological complexity
(consonant inventory size, vowel inventory size, suprasegmentals, syllable
complexity), not quite the same thing as what Atkinson measures, but
certainly getting at the same thing.  My figures for population size may
be different, as they are often based on grammars and ethnographies rather
than Ethnologue and I have attempted to track ethnic group size, not
numbers of speakers (since the proportion of speakers in ethnic groups has
fallen drastically in recent years).  Atkinson has 500+ languages; I have
85, representing that subset of the Autotyp (Bickel & Nichols 2002ff.)
genealogical sample that I was able to cover quickly.

I found the same positive correlation worldwide (statisticaly
significant).  But it does not obtain within large areas.  It is reversed
in Africa (a negative correlation: larger population correlates with
simpler phonology) and there is no correlation in Eurasia and the
Americas; there is a slight correlation in the Pacific, but my sample from
there is too small to be confident of this.

If there is really a correlation between population size and phoneme
inventory size (or anything else), it should hold within areas as well as
worldwide.  I believe the worldwide positive correlation is an artifact of
(a) larger population size in Eurasia and Africa, (b) areality in greater
Africa (extending into the Near East and the Caucasus) (large number of
airflow contrasts in consonant inventories).  (Africa is large but a
closed area which has received almost no linguistic or genetic
immigrations during its very long prehistory and the net effect of
numerous local contact episodes is continent-wide areality manifesting
itself not only in consonant contrasts but also e.g. in gender systems and
tone systems.)

Atkinson's explanation is that the smaller phoneme inventories in places
distant from Africa are founder effects:  as small populations migrated
greater and greater distances from Africa they passed through bottlenecks
and isolation and lost phoneme diversity.  If this is the actual
explanation, one would expect concomitant simplification of morphology and
the rest of grammar with greater distance from Africa, but in fact we find
the reverse:  languages in the Americas and the Pacific are on average
more complex overall, and morphologically, than those in Africa (or Africa
plus Eurasia) (Nichols 2009).


References

Atkinson, Quentin D.  2011. Phonemic diversity supports a serial founder
effect model of language expansion from Africa. Science 33:346-9.

Bickel, Balthasar and Johanna Nichols. 2002. The Autotyp research program.
http://www.uni-leipzig.de/~autotyp/

Dahl, Östen. 2004. The Growth and Maintenance of Linguistic Complexity.
Amsterdam: Benjamins.

Diamond, Jared. 1997. Guns, Germs, and Steel: The Fates of Human
Societies. New York: Norton.

Hay, Jennifer and Laurie Bauer. 2007. Phoneme inventory size and
population size. Language 83:2.388-400.

Sproat, Richard.  2011.  Science does it again.
http://www.cslu.ogi.edu/~sproatr/newindex/atkinson.html   (accessed April
14, 2011)

Szmrecsanyi, Benedikt and Bernd Kortmann. 2009. Between simplification and
complexification: Non-standard varieties of English around the world. In
Geoffrey Sampson, David Gil and Peter Trudgill, eds., Language Complexity
as an Evolving Variable, 65-79. Oxford: Oxford University Press.

Trudgill, Peter. 2009. Sociolinguistic typology and complexification. In
Geoffrey Sampson, David Gil and Peter Trudgill, eds., Language Complexity
as an Evolving Variable, 98-109. Oxford: Oxford University Press.