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.

The dialects of North American English

Divergence in North American Dialects

Word Phrase Sentence

1. _________ ________________ ___________________________

2. _________ ________________ ___________________________

3. _________ ________________ ___________________________

4. _________ ________________ ___________________________

5. _________ ________________ ___________________________

6. _________ ________________ ___________________________

The Northern Cities Shift: from the Project on Cross-Dialectal Comprehension: Gating Experiment 2

Percent correct in Gating Experiment for Chicago “busses with the antennas on top”

0

20

40

60

80

100

Word Phrase Sentence

Percent correct

Bir-ColBir-HSChi-ColChi-HSPhi-ColPhi-HS

Age distribution of F2 of /ʌ/ in the North

Age distribution of F2 of /ʌ/ in the Midland

Age distribution of F2 of /ʌ/ in the North and the Midland

age coefficient = 1.39

p = .033

age coefficient = - 2.05

p = .026

North Midland

Divergence in North American Dialects

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

The Canadian Shift

Probability matching

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

1550 Hz

/o/

/oh/

/æh/

A stable distribution of English low vowels: an outlier not recognized as a member of the /o/

distribution.

1571 Hz

/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 requiresalternating states of bidirectional changes followed by unidirectional changes in the form of mergers or chain shifts

A model of requirements for divergence

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 thelinguistic 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, a2Equally likely resolution of an unstable linguistic situation

The initiation of divergence

a1, a2Inconsistent 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, a2Inconsistent 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 merger

Increase 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

Irreversible

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. . .

Territoriality Local identity

Dominance and submission Style shifting and accommodation

Sexual selection The social construction of gender

Biological terminology Sociolinguistic terminology

0

10

20

30

40

50

60

70

œ o oh e U

Percent advanced tokens

Male Jocks

Male Burnouts

Female Jocks

Female Burnouts

Source: Eckert 2000

Gender and social category determination of five elements of the Northern City Shift in a Detroit suburban high school

ʌæ

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”

Age Female Years of25 yrs Gender Education

AE1 34*

8.6*

EAEQ 34* 26*

EOD 112*** H.S. -68*

UOD 37 -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.

The U.S. at night

U.S. at NightThe Inland North

Rochester

Detroit

Syracuse

Buffalo

Cleveland

Chicago

Milwaukee

Toledo

Grand Rapids

Flint

Joliet

Kenoshat

Columbus

IndianapolisCIncinnati

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]

South North1848Fillmore / /1852Pierce (D) D1856Buchanan D R1860Lincoln D R1864Lincoln S R

1868-1876 Reconstruction1880Garfield D R1884Cleveland D (R)1888Harrison D R1892Cleveland D /1896McKinley D R1900McKinley D R1904Roosevelt D R1908Taft D R1912Wilson D (D)1916Wilson D R1920Harding (D) R1924Coolidge D R1928Hoover / R1932Roosevelt D D1936Roosevelt D D1940Roosevelt D (D)1944Roosevelt D /1948Truman / /1952Eisenh’r / R1956Eisenh’r / R1960Kennedy / /1964Johnson / D1968Nixon W /1972Nixon R R1976Carter (D) /1980Reagan (R) (R)1984Reagan R (R)1988Bush R (D)1992Clinton / D1996Clinton / D2000Bush R D2004Bush R D

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

1,000

10,000

100,000

1,000,000

10,000,000

0 50 100

Percent Kerry vote by county

Total county vote

Inland North

North

Midland

New England

St. Louis

W. Pa.

Mid-Atlantic

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

Analysis 1 Analysis 2 Variable Coefficient prob Coefficient prob Constant 43.81 ≤ 0.0001 46.10 ≤ 0.0001 North 8.81 0.003 8.04 0.0118 Inland North 6.11 0.0356 9.06 0.0034 New England 20.46 ≤ 0.0001 18.77 ≤ 0.0001 Mid-Atlantic 15.56 0.0007 18.24 0.0002 Western PA 7.55 0.0708 7.90 0.0809 St. Louis corridor 5.74 0.2696 6.90 0.2206 County vote (million) 17.44 ≤ 0.0001 Adjusted r2 0.34 22.3

County vote for Obama 2008 by county vote and dialect

1,000

10,000

100,000

1,000,000

10,000,000

0 50 100

Percent Obama vote by county

Total County Vote

Inland NorthNorthMidlandNew EnglandSt. LouisW. Pa.Mid-Atlantic

C

Variable Coefficient prob

Constant 57.25 ≤ 0.0001

Inland North 3.21 0.056

Mid-Atlantic 7.75 0.021

New England 4.44 0.071

r2 = .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 [1994], 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 [2000], 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 listeners N

Inland North 9

Chicago 9

North (outside of IN) 1

Transitional (Ft. Wayne) 3

Midland 58

Indianapolis 4

Indiana 50

Other Midland 4

Mid-Atlantic 6

Canada 1

South 4

West 6

Mixed 2

90

Cities assigned to Detroit and Indianapolis speakers by student listeners at Indiana University [N=90]

Speaker assigned to Dialect

Speaker from

Detroit

Speaker from

IndianapolisChicago Inland North 24 3Detroit Inland North 26 4Michigan Inland North 5Cleveland Inland North 1Minneapolis North 2Fort Wayne, So. Bend Transitional 4Indianapolis Midland 6 24Indiana Midland 3 4Other Midland Midland 1 3Ky, Tn Upper South 1 12Atlanta South 1Denver West 1Total 74 51

Political opinions ascribed to an Inland North (Detroit) and Midland (Indianapolis) speaker by students at U. of

Indiana, Bloomington [N=90]

3.5

3.7

3.9

4.1

4.3

4.5

4.7

Abortion Affirmative action Gun control

Approval ->

Inland NorthMidland

p < .03 p < .003

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

1830-1860Westward 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/