Evolution of Language and Gestural Theory of Corballis

1. Evolution of
Language
Sinan Onur Altınuç

2. Contents
Introduction
Properties of Human Language
Different Views on Language
Gestural Theory (Corballis)
How Grammar Evolved
Conclusion

3. Introduction
Human Language and Evolution

4. Human Language
Different from other species
Vocal Properties
Generative Properties
Chomsky’s Claims
Too complex to be
explained by
behavioralism

5. Evolution
“Language is too complex to
be explained in terms of
natural selection”
“If it could be demonstrated that any complex
organ existed, which could not possibly have
been formed by numerous, successive, slight
modifications, my theory would absolutely break
down. But I can find no such case.”
Chomsky Darwin

6. Evolution and Language
Language cannot be
evolved with natural
selection. It has
emerged instantly
through a catastrophic
event.
Evolution of language
can be explained by
successive
modifications and
natural selection

7. Theodosius Grygorovych Dobzhansky, 1973
Nothing in biology
makes sense
except in the light
of evolution.

8. Evolution of Apes

9. Evolution of Human Primates

10. Properties
of Human Language

11. Hemispheric Asymmetry
Asymmetry in left hemisphere
Caused from enlarged Planum
Temporale (PT)
Language capabilities in humans
Originally thought only present in
humans
Similar asymmetries were found in
primates like chimpanzees(Gannon et al.,1998b)
Interspecies communication

12. Left Hemispheric Areas
Planum temporale
Wernicke
Broca’s
Lesion Studies
Intraoperative Electrocortical
Stimulation Mapping (IESM)
Neuroimaging
Studies
Both humans and nonhuman
primates have specialized areas

13. Difference of Human Language
Vocal Communication
Flexibility of expression
Flexibility of structure
Generativity
Can be acquired just by exposure
Chomsky: Universal Grammar

14. Cross Modularity
Language can be:
Spoken/heard
Signed/seen
Written/seen
Brailled/touched
Transmitted/received
Sign Languages

15. Different Views
on evolution of language

16. Hauser, Chomsky, Fitch
Before evolution language must be
understood
Faculty of Language
Broad sense(FLB): Sensory, conceptual,recursion
Narrow sense(FLN): Recursion, uniquely human
FLN cannot be explained with natural
selection is a by-product of evolution.

17. Pinker and Bloom
“Natural Selection and Natural Language” (1990)
Support Universal Grammar
Difference from Chomsky:
Language shows properties of complex design
Only way to understand complex design in nature is to
resort to evolution

18. Bickerton
We should think about 2 things:
I) How did symbols evolve?
II) How did syntax evolve.
“The fear of Syntax”
Syntax is too complex to be explained by evolution and natural selection.
Syntax is just ordering of the words.
Protolanguage
A leap from protolanguage to language

19. Jackendoff
Similar to Bickerton’s on protolanguage.
The evolution from protolanguage to language
can be explained by gradual evolution and
incremental adaptive improvement.

20. Tomasello
Rejects Universal Grammar
Unfalsifiable
Language Universals:
There are universal language elements
They are not related to linguistic structures
The result of cognitive capabilities

21. Gestural Theory
Corballis

22. Gestural Theory
Manual gestures
Facial Gestures
Understood by sound
Gradual evolution

23. Basis for Gestural Theory
Different varieties have structural sophistication
Nonhuman primates like chimpanzees and bonobos
provide best proxies for earlier abilities.
Not capable of vocal learning
Can Communicate by gestures
Shared Attention
nonhuman primates lack

24. Mirror System
Mirror Neurons F5 area (Rizzolatti al., 1996)
Broca's Area (BA 44,45)
BA 44 homologous with F5 in primates
Extended mirror system in monkeys overlap
language circuits in humans
Language is part of the mirror system.

25. From Hand to Mouth
Gestures
primary system in primates
Critical weakness
Gesture theory cannot explain
shift from hands to mouth
Speech is gestural system

26. Adding Sound
Facial gestures recoverable by mirror system
via sound
Primates: Tearing of paper Cracking of peanuts (F5)
Mutation of FOXP2
Cooption of vocal control in Broca’s
2 Mutations since split between hominin and
chimpanzee lines.

27. Anatomical Change
Other anatomical changes required for
speech production:
Hypoglossal canal nerve
Abdomen and throat muscles
Roundness of cranial vault
increased size of temporary and/or
frontal lobes
African click languages

28. Why Switch
Disadvantage:
Increased risk of
choking
Advantages:
Communication at night
Less energy consuming
Carrying things, using and
making tools

29. How Grammar
Evolved
according to Corballis

30. How Grammar Evolved
Unlimited expressive freedom
Grammatical language can be prior to spoken
language
Arise from more general cognitive capabilities

31. Mental Time Travel
Episodic Memory (Tulving, 1972)
REsulted in mental time travel
Conjure past and plan about future
Narrative
Imagined events, coherent structures
Communicate our travels to others
Cognitive Niche
relying on social corporation, planning and information exchange

32. Symbols and Mime
Bipedalism - > Mimetic culture
Events were related to body and hand
movements
Still persists in dance
Iconic representations to
spatiotemporal mapping
Convenzaliation: becomes arbitrary
Speed up

33. Generativity
Languages cannot be explained in terms of
learned sequences.
Combinatorial structure derives from
combinatorial structure of episodes and
word provide access to components of
episodes
Can’t explain why amnesics don’t have problem.

34. Grammaticalization
Grammar: a device for making
communication more efficient and
streamlined
Nicaraguan Sign Language
Children develop their own sign language
Cat swallowed a bowling ball rolled down a step
2 different versions
Short version persisted for other generations

35. Conclusion

36. Conclusion
Human language capabilities
Evolution is gradual or not?
Corbalis’ work
Based on mirror system
Facial gestures articulated by sound
Evolutionary advantages
Universal Grammar and Evolution of Grammar
Mental time travel
Conventionalization
Grammaticalization

37. Evolution of
Language
Sinan Onur Altınuç