Presentation on theme: "Conditions for Divergence and Convergence in the Micro-Evolution of Language William Labov, University of Pennsylvania Penn Linguistics Colloquium March."— Presentation transcript:
Conditions for Divergence and Convergence in the Micro-Evolution of Language William Labov, University of Pennsylvania Penn Linguistics Colloquium March 27, 2009
No scientific theory is worth anything unless it enables us to predict something which is actually going on. J.B.S. Haldane, cited by P. & R. Grant
(1)When two groups are separated so that communication between them is reduced, then divergence is expected, and any degree of convergence requires an explanation. (2)When two groups are in continuous communication, linguistic convergence is expected and any degree of divergence requires an explanation.
Growing divergence in North American English Recent studies of linguistic change in progress in North American English show increasing diversity on a regional scale, along with some degree of local convergence.
Relationships among America ’ s Most Populous Metropolitan Areas
Three suggested parallels of linguistic and biological evolution 1.Probability matching (Gallistel 1990) → the mechanism of chain shifting 2.Microevolution (P. & R. Grant 1993) → the mechanism of divergence 3.Animal communication systems (Cheyney & Seyfarth 200 → the social motivation of linguistic change
Experimenter 1: every 5 seconds every 10 seconds Experimenter 2: every 5 seconds every 5 seconds Mean number of out of 33 ducks in front of experimenter 1 as a function of time and rate of throwing food (Gallistel 1990)
Phonemes co-existing in a language tend naturally to optimize the possibilities that are available from the speech organs; they tend to be as distant from their neighbors as possible while remaining easy to articulate and easy to perceive... Martinet 1955:62 (tr. WL), attributed to de Groot TCLP 1931:121 Martinet on maximal dispersion
/o/ /oh/ /æh/ A stable distribution of English low vowels: an outlier not recognized as a member of the /o/ distribution.
/o/ /oh/ /æh/ An unstable distribution of English low vowels: /æh/ shifted up and front so that the /o/ outlier affects the central tendency of /o /
Opposing chain shifts in North America Northern Cities Shift Southern Shift
Model of divergence The divergence of neighboring dialects requires alternating states of bidirectional changes followed by unidirectional changes in the form of mergers or chain shifts
Micro-evolution The fluctuations of bidirectional changes resemble the micro-evolution of finch beaks in the Grants' study of the Galapagos, although no correlate of fitness or natural selection has yet been identified for the linguistic changes
Bidirectional micro-evolution The population of medium ground finches, Geospiza fortis, experienced size-selective mortality during a drought in 1976-77; large birds with deep beaks survived better than small birds. During another drought, 1984- 1986, the population experienced selection in the opposite direction on beak traits. Changes in food supply were the apparent causes of selection on beak traits in both episodes. --Grant, Peter R. and B. Rosemary Grant 1994. Predicting microevolutionary responses to directional selection on heritable variation. Evolution 49:241-251.
The initiation of divergence a1, a2 Equally likely resolution of an unstable linguistic situation
The initiation of divergence a1, a2 Inconsistent mixture of short-a tensing patterns Nasal system: tense all /æ/ before nasals General tensing and raising of all /æ/-> /æh/ Reversible
The initiation of divergence a1, a2 Inconsistent mixture of short-a tensing patterns Nasal system: tense all /æ/ before nasals General tensing and raising of all /æ/-> /æh/ Northern Cities Shift Northern Cities Shift blocked
The development of divergence /o/ ~ /oh/ Skewed opposition depending on length Low back mergerIncrease phonetic distance Northern Cities Shift Pittsburgh chain shift Canadian Shift Back vowel shift Back upglide chain shift Inland North: front /o/ Eastern seaboard: raise /oh/ South: add upglide Reversible ) ) ) Irreversible
Natural selection ( ? ) To summarize, the co-existence of finch species is facilitated by divergence in beak morphology and song. Beaks diverge under natural selection, but why songs diverge is less clear. Cultural drift, a process of random change in culturally transmitted (learned) traits, is probably involved, and sexual selection may be learned as well. What Darwin's Finches Can Teach Us about the Evolutionary Origin and Regulation of Biodiversity B. Rosemary Grant and Peter R. Grant, Bioscience, Vol. 53, No. 10 (Oct., 2003), pp. 965-975
Beak evolution Evolution of beak depth of Geospiza fortis for survivors of 1976 drought, for 1976 offspring and 1978 offspring. --B. & P. Grant 2003.
Cheney and Seyfarth on the role of social intelligence Baboons’ adaptive specialization is their social intelligence; their technological skills are underwhelming...Although innovation, tool use, and technological invention may have played a crucial role in the evolution of ape and human brains, these skills were probably built upon mental computations that had their origins and foundations in social interactions. --Cheney and Seyfarth 2007:283.
Social factors as adaptive forces in linguistic behavior... TerritorialityLocal identity Dominance and submissionStyle shifting and accommodation Sexual selectionThe social construction of gender Biological terminologySociolinguistic terminology
Source: Eckert 2000 Gender and social category determination of five elements of the Northern City Shift in a Detroit suburban high school ʌ æ
The individual creates his systems of verbal behavior so as to resemble those common to the group or groups with which he wishes from time to time to be identified, to the extent that: (a) he is able to identify those groups (b) his motives are sufficiently clear-cut and powerful (c) his opportunities for learning are adequate (d) his ability to learn -- that is, to changes his habits where necessary -- is unimpaired. --R. Le Page & A. Tabouret-Keller, Acts of Identity (1985) “Acts of identity”
AgeFemaleYears of 25 yrsGenderEducation AE1 34* 8.6* EAEQ34* 26* EOD112***H.S. -68* UOD37 -16* Social correlates of four measures of the Northern Cities Shift [N=71]
A consideration on large-scale social factors African-Americans in Memphis appear to be moving toward forms which symbolize involvement in the Southern community and its associated heritage... While social unity was a part of the communities of practice explored by Eckert, I would expand her framework to suggest that these shared practices do not necessarily require individuals’ social cohesion but merely require shared historical experience and a strongly circumscribing environment that places speakers in a similar social position relative to the external social world. ----Fridland 2000
A large scale phenomenon The Northern Cities Shift is found throughout the Inland North, an area of 88,000 square miles. A population of over 34,000,000 speakers of American English are participating in this shift.
U.S. at Night The Inland North Rochester Detroit Syracuse Buffalo Cleveland Chicago Milwaukee Toledo Grand Rapids Flint Joliet Kenoshat Columbus Indianapolis CIncinnati Kansas City Omaha St. Louis
Red States and Blue States in U.S. 2004 Presidential election
The Northern dialect region mapped on to Red States and Blue States in U.S. 2004 Presidential election
Presidential elections in which the Northern States [NY, MI, WI, IA, MN] have been opposed to the Southern States [TX, AK, LA, MI, AL, GA, FL, SC, NC, KY,TN, VA]
Democratic vs. Republican vote for counties surveyed by dialect in presidential election of 2004. Inland North Midland New North England Kerry majority 20 15 8 12 Bush majority 6 7 13 2
County vote for Kerry 2004 by county vote and dialect Bush Kerry
Regression analyses of county percent vote for Kerry in 2004 by dialect groups with and without total votes as independent variable. Residual group: Midland
County vote for Obama 2008 by county vote and dialect
VariableCoefficientprob Constant57.25 ≤ 0.0001 Inland North3.210.056 Mid-Atlantic7.750.021 New England4.440.071 r 2 =.065 Regression analysis of 2008 Obama vote by county
Passage 1 in Experiment 1 (from Sabrina K., 37, Detroit MI, TS 176) The--the way I got hired for this one job was really weird, ‘cause I went in for a... secretarial position is what I went in for, and they had hired...ah-- somebody else that didn’t know anything, but it was a buyer’s daughter, so then she got the job. And uh-- they called me because I had done shipping and receiving as far as--the paper work, and they had asked me if I‘d help out ‘cause their--shipper had just had a heart attack and she wasn’ comin’ back for a while. short o fronting short a raising oh lowering
The Northern Cities Shift of Sabrina K., 37 , Detroit MI, TS 176 Short-a Short-e Short-o Short-i Long open o Short-u
Passage 2 in Experiment 1 (from Mimi P., 45 , Indianapolis IN, TS 775) short o back of center tense a before nasals; lax a, e in that aw fronting ^ fronting I read, a-n-nd like most women, I like to go shopping and play card games with family and friends and that kind of thing, nothing really exciting. We used to go camping quite a bit on the weekends, but our lives have shifted enough that we don’t do that much right now, but uh that’s what we do.
Dialect areas in which U. of Indiana subjects were raised [4-13 yrs of age] Dialect area of listenersN Inland North9 Chicago 9 North (outside of IN)1 Transitional (Ft. Wayne)3 Midland58 Indianapolis 4 Indiana 50 Other Midland 4 Mid-Atlantic6 Canada1 South4 West6 Mixed2 90
Cities assigned to Detroit and Indianapolis speakers by student listeners at Indiana University [N=90]
Political opinions ascribed to an Inland North (Detroit) and Midland (Indianapolis) speaker by students at U. of Indiana, Bloomington [N=90] No significant difference in judgments of intelligence, trustworthiness, education; Midland speaker judged more friendly (p <.00001)
Ideological, political and linguistic developments, 1817-2008 Expansion in western NY Evangelical movement Opposition to racial inequality Switch of political allegiance 1825-50 Raising of short-a 1817-1825 1830-1860 Westward expansion Party of racial equality 1960-1995 2000-2008 1860-1956 Blue States /Red States redefined Perfectionism 1967 Fronting of /o/ first reported 1960 Democratic 1986 Backing of / ʌ / first reported 1856 Republican No ’ n Cities Shift Yankee ideology Yankee settlement
Means of 14 vowels in peripheral/nonperipheral phonological space. IN = Inland North IN /æ/ IN /e/ IN /o/ IN / ʌ /