Collaborative Commentary - MacWhinney1
The Sudden Evolution of Language? -- Pillar #6
Brian MacWhinney Psychology
Carnegie Mellon
Collaborative Commentary - MacWhinney2
The Seven Pillars of UG
1. Grammar Gene2. Speech is Special3. Language Organ and Modularity4. Critical Periods5. Poverty of the Stimulus6. Sudden Evolution of Language7. Recursion - LND
Collaborative Commentary - MacWhinney3
Data Sources
1. Direct Evidence• Genetics• Fossils, reconstructions, comparative physiology• Settlement patterns, habitat range• Tools, artifacts, art• Climactic changes - glaciation, eruptions
2. Indirect Evidence Human ontogeny, language acquisition Neurology Linguistics -- function, gesture, phonology, recursion Evolutionary Psychology All of the above across other primates and other
species
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Core Issues
• Saltation vs. Coevolution• Developing an account that is consistent with the
observed data• Recent focus by Hauser, Chomsky, Fitch on
recursion as the core of language• Can we use this account to predict new findings
and results in: Comparative behavior Comparative neurology Fossils, tools, settlement, genetics Evolutionary Neural Networks Evolutionary Psychology
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Lessons from Child Language
Language learning involves linking a series of abilities Audition Segmentation Imitation Articulation, Timing Attention Lexicon Combination Recursion ….
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Lessons from Functional PsychoLinguistics
• Language is grounded on cognition in Direct perception Space/Time/Aspect deixis Causal Roles Social Roles
• Each level is organized by perspective• Incremental processing starts from
embodied core -- McNeill• Compilation relies on item-based patterns
and recursion
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Lessons from Evolutionary Theory
• Adaptations must lead to individual reproductive advantage
• Group advantages are secondary• Advantages can be linked to
disadvantages (sickle cell, autism)• Populations are dynamic• Changes are gradual and emergent -
but this is still debated
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Skill Network
• Each attainment builds on previous ones.• Each relies on abilities that are found in a
more limited form in our primate cousins.• Each ability can in turn be decomposed
into subcomponents.• Given this, simple saltation is impossible.• However, some key changes could foster
productive co-evolution of the network.• What forces could support continued
progress?
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Continued Support
• The shift to bipedalism continued across three million years.
• The role of the freed hands changed over time, but was a continuing drive.
• Social forces exerted continual pressure.
• Social forces combined with the role of the hands.
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A Grounded Social Climber
• As a bipedal, man is like the kangaroo.• Unlike the kangaroo, hominids were
climbers who used their hands.• The hands were then used to control
tools, but …• Forced into face to face contact, the
hands could also contribute to social interaction.
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Proto-Mimesis
• Bipedalism opens up face-to-face contact
• The hands operate in the contact area
• This produces proto-mimesis (Zlatev) with pointing and teaching
• Vocalization locks in attention
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Partial Differences
• Some ape lexical learning, but incomplete
• Some ape planning abilities (Goodall straws), but incomplete
• Some ape intersubjectivity, but incomplete
• Some ape pointing, but incomplete
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Sharper Changes
• Cortical control of vocalization• Duality of patterning - Recursion?• Brain expansion• Physical changes
Articulation - teeth, mouth Phonation - vocal cords, bent vocal tract Thumb Posture, parturition, neotony
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Problems with Saltationism
• Only deals with the last 100,000 years, not the last 6 million years
• Ignores 300% increase in brain size• Ignores many morphological changes• Ignores homo erectus expansion.• Fails to deal with gesture• Fails to deal with skill network• Etc…
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Five Periods
• Bipedalism 7-4 MYA• Social Cohesion 4-2 MYA• Mimesis 2-.2 MYA• Phonology 300,000 - 50,000• Creativity 50,000 - now
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Cognitive Attainments
• Bipedalism Basic imagery, tool use, spatial recursion
• Social Cohesion Cortical control of vocal-auditory channel
• Mimesis Gestural item-based pattern, prosody
• Phonology Phonemic system, phonological loop
• Creativity Item-based, perspective
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1. Bipedalism
• Coppens East Side Story 10-7 MYA• Jungle -> savannah (lakes?)
Handedness and affordances for arboreal Deixis for terrestrial
• Tool use and locomotion (primary)• Communication (secondary)• Groups needed for protection against
predators
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Neuronal Support
• Parietal reorganization at 4MYA- Holloway Body image projection Navigation and deixis Spatial images support recursion Facial recognition (supramarginal)
• Tools, navigation, social cohesion
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2. Social Cohesion
• Expansion at 4MYA, contraction at 3.5MYA• Habilis/ergaster vs. australopithecus• Competition was won by the most
cohesive and planful groups Good social partners Sexual arms race Dominance vs. external aggression Role of dialect marking Dunbar, Power, Worden social accounts
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Cortical Control of Vocalization
• Primate system links Arousal (amygdala, brainstem) Motivation (basal ganglion) Memory (limbic, hippocampus)
• The primate external striatum was absorbed by the neocortex, giving cortical control
• Control is now from the supplementary motor and anterior cingulate
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3. Mimesis
• Parallel evolution The gestural channel contained the content The vocal channel contained the social glue
• Disorganized nature of mimetic processes• Inefficient gestalt encoding• Mechanisms:
Imitation Pointing Joint attention (Intersubjectivity) Perspective-taking
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Monkey See, Monkey Do
• Whiten 2003 Patteson 1978
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Early Gestalts
• Mimetic patterns do not separate verbs and nouns
• Me-hand-grab-axe-up-swing-down-cut-chips-sound
• This can be imitated as a Gestalt, but Gestalt storage is expensive
• I chop wood.
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Satisfied Preconditions
• Hands were free• Hands were controlled by complex plans• Spatial maps had evolved for self and group• The visual system could generate and store
images• Visual images encoded hierarchically and
open to recursion• Vocalization and eye-gaze controlled
attention in face-to-face interaction
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Neuronal Support
• Tripling in brain size (some allometric)• Earlier growth was in specific areas
Parietal Cortical control of vocal channel
• New pressures Need for full simulation of the body for mimesis Storage of mimetic sequences Processing of mimetic operators Teaching of mimetic sequences by mothers Perspective-switching
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How successful?
• Expansion to all of Eurasia• At the expense of other hominids• Big, unorganized brain• No vocal systematization• Climate changes of the Pleistocene
led to new pressures
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4. Phonology
• Phonological patterning MacNeilage and vocal gesture Gupta and MacWhinney and the phonological
loop
• Making efficient use of lexical storage• Capitalizes on evolution in TOM and
perspective
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Vocal Adaptations
• Lower larynx and hence larger (and distinct) pharynx
• Longer local cords (at least in adult males)• Aerodynamical streamlined conus elasticus
(underside of vocal cords• Expanded neuronal control of intercostals at
300,000
These adaptations produce loud, efficient, and low-pitched vocalizations (but not necessarily speech itself).
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Facial Musculature
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Ears, Teeth
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Vocal Cords
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Source-Filter Theory
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Bent Vocal Tract
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Possible Vowels
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Neanderthal and Cro-Magnon
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Neuronal Support
• Broca’s for lip-smacking becomes Broca’s for CV syllabic framework
• Phonological loop involving superior temporal stores lexical items
• Lexical items have access to all of the brain, but not dynamically
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Reuse of earlier mechanisms
• Phonological store allows vocal rehearsal
• Hippocampus stores the episodic basis of lexical meanings
• DLPFC stores plans for tools use and mimesis
• Integrated frontal function constructs group relations: kinship, reciprocals, hierarchy
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5. Phoenix
• Narrowing of evolutionary window at 70,000
• Computed through females, but males must be similar
• Perhaps due to Toba Batak, perhaps to a pandemic
• Survivors were an interesting subset of the earlier population
• Phoenix from the Ashes
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Creativity Explosion
• Artifacts at 50,000 - carved bone, amulets
• Cave paintings at 30,000• Burial at 30,000• Opposition to Neanderthal• Mithen theory of demodularization
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Suspects
• Perspective• Recursion• Priesthood
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Perspective Hypothesis
directexperience
space/timedeixis
socialplans
perspective perspectiveperspective
language as a functional neural circuit
unified embodied image
perspective
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Evolution and Perspective
• The five periods do not match the four cognitive levels
• But each level was constructed as a part of this process
• Each was progressively refined over time
• The phonetic revolution underlies the grammar, but the grammar maps to cognition, not phonology
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But…
• TOM is developed in chimps• Perspective was important during
mimesis• Imitation was present• Imagery was present• Mirror neurons are in monkeys
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Recursion
• Next talk: What Chomsky means by recursion reduces to item-based patterns
• Item-based patterns require Items Slots Features Clustering
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Patterns from Combinations
• cookie = “would you please open the cupboard
door and bring me down a cookie”
• want ##### cookie• want # cookie• want cookie• Nim Chimpsky, Washoe, Sara, Lana
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Item-based Patterns
• my + X Position Meaning relation Possible fillers My little dolly
• Where + X Where the wheel goes? Where goes the wheel?
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Sockets are action-based
Throw____give__ __
--- breaks
__kick __ __ running
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Feature-based patterns
• big + X, nice + X ….• Adj + X• Adj + N• But what about?
Actor + Action Subject + Verb Topic + Comment
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Patterns to Creativity
• Item-based patterns provided full recursion
• Recursion linked dynamically to perspectival systems
• Articulate language users became priests
• Priests constructed the afterworld and myth
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Syntax and Perspective
• Tim saw the Grand Canyon flying to New York.
• Jessie stole a picture of *her/herself.• Jessie stole me a picture of her/*herself.• The adults in the picture are facing away
from us, with the children hidden behind them.
• Did the bicyclist appear to fall?• Tim couldn’t find Mary’s beloved cat.
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Social Perspectives
I claim that reason is a self-developing capacity. Kant disagrees with me on this point. He says it’s innate, but I answer that that’s begging the question, to which he counters, in Critique of Pure Reason, that only innate ideas have power. But I say to that, what about neuronal group selection? And he gives no answer.
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Conclusions
• Language evolution was gradual, relying on coevolution of language, thought and gesture.
• We can distinguish five major periods.• Recursion was important in recent
changes, but relied on earlier spatial patterns
• Most recent changes involves coordination of recursion and lexicon with perspective