1. Input vs. network effects in the multiagent modeling of morphological leveling in Old Castilian Harry Howard Tulane University LASSO 2006 Laredo, TX

2. LASSO 2006Harry Howard2 Tuten (2003) on koineization in the history of Spanish By the 11th century, (southern) Castilian differed strikingly from its Romance neighbors in the simplicity of its definite articles Castilian had almost reached its modern analyticity, with no allomorphs of the plural forms and only two preposition + article contractions (al, del). The only difference was allomorphy in the singular forms (el-elo; la-ela-l). In contrast, the other Ibero- Romance dialects were considerably more complicated, with multiple article allomorphs, as well as contractions onto the prepositions por, de, a, con, and en.

3. LASSO 2006Harry Howard3 Koineization Tuten attributes the simplicity of Castilian to koineization, and in particular to a process of dialect leveling that occurs when speakers leave established, monodialectal social networks whose members are bound together by strong ties and move into new, polydialectal social networks whose members are bound together only weakly. In the particular case of 11th century Castilian, Tuten see the initial stages of the Reconquest and the establishment of Burgos as the capital of its leading edge as supplying the conditions for the latter kind of society.

4. LASSO 2006Harry Howard4 Our response Tuten’s updating of a classic problem in Romance linguistics, conflates two causal factors, how language is learned in situations of multiple competing inputs (i.e. dialect mixing) how language is learned in situations of social innovation (i.e. weak social networks). Of course, there are no longer any native speakers of 11th century Castilian to interview, so Tuten cannot be faulted too harshly for not disentangling his causal factors more carefully.

5. LASSO 2006Harry Howard5 Our approach In fact, the lack of real native speakers means that the best we can do is construct artificial ones, via computer programs, and see how they behave as parameters are varied. This brings us to the realm of multiagent modeling, which has recently seen a burst of enthusiasm in the creation of sociolinguistic microcosms for the simulation of language evolution. De Boer’s (2001) investigation of the evolution of vowel systems provides a convenient starting point.

6. LASSO 2006Harry Howard6 Table 1. Definite article allomorphs in Galicia & Portugal

7. LASSO 2006Harry Howard7 The Western Mediterranean in 1030

8. LASSO 2006Harry Howard8 The algorithm 1. an agent chooses a meaning from its semantic memory. In our simulations, this will be an unexpressed noun with features for gender and number, plus a preceding context, either one of the five prepositions or not. 2. the phonemic representation of the meaning is retrieved from memory, converted to phonetic form, and ‘spoken’ to another agent, which 3. matches it to its phonemic memory, in order to 4. retrieve a meaning which 5. it tries to match against the meaning intended by the speaking agent. If there is a match, 6. the hearing agent stores the phonemic-semantic association.

9. LASSO 2006Harry Howard9 Table 2. Vectors for the gender and number features of Ibero-Romance nouns

10. LASSO 2006Harry Howard10 Table 3. Vectors for Ibero-Romance free and prepositional contexts of article allomorphs

11. LASSO 2006Harry Howard11 (1) Phonemes for Ibero-Romance definite article allomorphs vowels: /(i), e, a, o, u/ consonants: /k, d, s, n, l, r, p/

12. LASSO 2006Harry Howard12 (2) Hubey’s (1999) three dimensional phase space of acoustic-articulatory events x) stricture quality, the area (length*width) of a stricture multiplied by its characteristic frequency ω measured in radians/sec = l*w*ω. y) stricture change, the time derivative of the change in stricture area = d/dt (l*w)*ω. z) quasi-Reynold’s number, found by multiplying the characteristic length (K) by velocity (v = l /time) = K*v.

13. LASSO 2006Harry Howard13 (4) Hubey’s approximations x) stricture quality = {{k,g,x,h}, r, {l,s,z}, {d,t,  }, {f,v}, {p,b,m}} y) stricture change = {{vowels}, {dipthongs}, {r,l,m.n,s,f, ,x,h}, {b,d,g}, {p,t,k}} z) Reynold’s number = {{vowels, dipthongs}, {r,l,m,n}, {v,z}, {s,f, ,x,h}}

14. LASSO 2006Harry Howard14 Table 4. Phonemic vectors for the Ibero- Romance definite article allomorphs

15. LASSO 2006Harry Howard15 Table 5. Word matrix for Galician-Portuguese pola

16. LASSO 2006Harry Howard16 Figure 1. Fifteen [l], made by adding noise with mean 0 and standard deviation 1 to /l/

17. LASSO 2006Harry Howard17 Figure 2. Frequency of Galician-Portuguese morphemes idealized at 1:3:5

18. LASSO 2006Harry Howard18 Figure 3. Development of Galician- Portuguese morpheme categories towards 1:3:5

19. LASSO 2006Harry Howard19 Figure 4. Imperfect development of Galician-Portuguese morpheme categories

20. LASSO 2006Harry Howard20 Production A simple algorithm for leveling the preposition-article contractions: Use more frequent forms over less frequent ones Note that the less frequent forms will be even less frequent in the environment of 13th century Castilian, since there were also competing forms from Leonese, and Aragonese, as well as Northern Castile

21. LASSO 2006Harry Howard21 The social model It appears that strong ties/dense social networks are necessary to maintain less frequent forms, but it could also be that such societies are more isolated or less porous to outsiders