Mt. Iso in PNG, 12 miles southwest of Sumo, east of the Catalina River. Diuwe is spoken between sea level and the first isoline at 100m, Hidbap between the first and the second isolines.

This week, the language of the week at Anggarrgoon is DIY, also known as Diuwe. Claire Bowern, noting that the only comment in the Ethnologue entry of the language is the terse and rather mysterious ‘Below 100 meters’, claims that the phonology of DIY shows an effect of altitude on air stream mechanisms. I thought I would shed some light on this curious situation by profiling Hidbap, a language related to Diuwe.

Hidbap is Diuwe’s closest neighbour both geographically and phylogenetically. It is a language spoken above 100m but below 200m in the same area as Diuwe, that is, 12 miles southwest of Sumo, east of the Catalina River. Like Diuwe, it has exactly 100 speakers. The languages are quite closely related, though there is no mutual intelligibility due to the presence of a large bundle of isoglosses at the 100m isoline. Speakers of either language avoid crossing into each other’s territories at all cost (see below).

Altitude as a determinant of linguistic structure

The split between the two languages is thought to have occurred some 600 years ago, when volcanic activity caused the previously flat territory to bulge up to a height of almost four hundred meters, forming the geolinguistic oddity that has since become known as Mt. Iso.1 The people, formerly speakers of mere dialectal variants arranged in a concentric circle, suddenly found themselves on different altitudes separated by black isolines (see map above). Given the close association between black lines and danger in this culture, they were less than eager to cross the isolines, which resulted in the lects developing in isolation from each other for several centuries. It is well known, of course, that phoneme inventories belong to the linguistic structures that are most susceptible to change, and the peculiar geography of the Iso district has given rise to some rather curious changes in this respect indeed.

Claire Bowern’s claim that Diuwe is ‘the only language which supports the hypothesis that altitude affects air stream mechanisms’ is a bit problematic, as this is the kind of hypothesis that is difficult to prove or disprove based on only one language. Fortunately, Hidbap provides just the kind of data that is needed to make a case for the effect. As it happens, Hidbap has a phoneme inventory which is quite similar to that of Diuwe as far as places of articulation go, but the consonants, rather than being pulmonic egressive as in Diuwe, are all implosives and ejectives. It thus seems that, apart from change due to contact and change due to internal drift of the system, we have to recognize a third factor bringing about language change: altitude.

This of course raises the question whether we can enlarge our sample of altitude-affected inventories to get a better view of the phenomenon. Nothing much is known currently about the parts of the Iso district that lie above the second isoline,2 though some intriguing oral traditions have been recorded among the Diuwe and the Hidbap about abnormal types of speech in the upper regions of the district.3 Calling all Papuan experts of the blogosphere! Language Hat, Omniglot, Blogazonia, Jabal al Lughat, matjjin-nehen, Alf Lisan, Tulugaq, the Papuan specialists at Language Log, and of course those Papuan bloggers than I’m not yet aware of, can you help us out?

References

1. Foley, W. A. 1986. The Papuan Languages of New Guinea. Cambridge: Cambridge University Press.
2. Michael, Lev. 2008. Cultural constraints on Aharip grammar, on Greater Blogazonia, May 8, 2008.
3. Sapir, Edward. 1915. Abnormal types of speech in Nootka. Geological Survey, Memoir 62, Anthropological Series No. 5. Government Printing Bureau: Ottawa. [Reprinted in Mandelbaum (ed.) 1949, pp. 179-196]

1. Cf. Michael 2008. In a helpful act of fact-checking, Language Log commenter rootlesscosmo notes that this is the Mt. Iso that was first mapped by the intrepid geographer Dr. Cline. [↩]
2. Foley (1986), for one, is silent on the matter. However, see the recent study of Aharip by Michael (2008). [↩]
3. Cf. Sapir 1949[1915]:194, who notes that tribal speech speculiarities are often the target of mocking forms. [↩]