1. Evolution of Human Language
Carissa Fletcher
2.4.2012

2. Contents
• Define language and its components
• Relationship to social learning
• Theories on how language evolved
• Empirical evidence from NHP research
• Evidence from genetics and the fossil record

3. Definition of Language
“language can be defined as the bidirectional
system that permits the expression of arbitrary
thoughts as signals and the reverse
interpretation of those thoughts”Fitch, Huber and Bugnyar (2010)

4. Who has language?
Animals have communication systems that allow
some biologically important information
concepts or emotions to be expressed vocally or
visually.
However, humans are unique in possessing a
system which allows any concept to be
expressed and understood.

5. Components of human language in the
broad sense
Syntax Semantics
Human
Language as
Large
an emergent
memory
property
Phonology Pragmatics
Fitch 2010

6. Definitions
Term Components Nature
Syntax - Word stems, affixes Computational. Structure generating
- Phrases, sentences mechanisms that map between signals
- Rule governing combinations and concepts.
- Hierarchical (
- Recursive/self embedding
Phonology - Phonemes (fricatives, nasals, plosives Physical. Perceptual and motor systems
m, p, b, f,v) underlying speech. Also, the process of
- Arranged hierarchically into syllables learning requires close imitation.
- Intonation, stress, prosody, rhythm
- Double articulation
Semantics - Meaning in the language Philosophical. Central cognitive
mechanism supporting concept
formation and expression
Pragmatics -What the speaker intends Psychological. Requires an ability to infer
- Mittelungsbedurfnis intentions of a signaller which can be
- (Shared attention system, Theory of based on indirect cues such as ‘gaze
Mind mechanism direction’. Also, sharing inner thoughts
relies on an understanding of the
thoughts of another (ToM)

7. Language – its relationship to social
cognition and culture
Advanced social cognition is
required for children to acquire
language as sophisticated “mind
reading” abilities needed to
Social Language
deduce word meanings and to cognition
communicate pragmatically.
Once in place language itself
becomes a tool for social
cognition becomes central to
Human Culture.

8. Language diversity
- Over 6000+ different
languages globally
- Darwin saw
similarities between
the evolution of
species and the
evolution of
languages.
Grey et al. 2010 NeighborNet analyses of the Indo-
European linguistic items

9. Theories on how language evolved?
1. Innate biological system
- System of cognitive structures develop and
are genetically determined.
- There are some shared computational
commonalities between all languages e.g.
Universal Grammar
(Chomsky 2007)
- language syntax shows evidence of complex
design – similar to, for example, the visual
system. “biological adaptation is the only way
to explain the appearance of such design”.
(Pinker 2003; Nowak 2001)

10. 2. Usage based system:
- Human language is symbolic
- We evolved cognitive skills enabling the use of
symbols
- 'social-cognitive' and 'social-motivational'
infrastructure needs to be in place before
language could arise in humans.
- Human communication is a fundamentally
cooperative enterprise that could not have arisen
without the shared intentionality.
- Shared intentionality allows for the emergence
of naturally intention directing gestures
(pointing and miming)Tomasello(2008)

11. 2. Usage based system:
- The close relationship between
manual gesture and vocalization(in
the form of speech via mirror
neurons Corballis (2003)
- Cooperative hunting, food savaging
and food sharing have been
powerful drivers of the information
sharing capacity embodied in
language.
- suggested that the capacity
Bickerton (2010)
of displacement in human language

12. Comparative approach
1. Shared vs
Unique?
2. Gradual or non-
gradual evolution
of this feature?
3. Continuity or
exaptation? Fitch 2010

13. Vocal Production in Primates ~ 63Mya
- NHP calls develop under
strong genetic influences
(Hammerschmidt and Fischer 2008)
- Vocal plasticity in NHP the Mouse
form of acoustic lemur
convergence at the group
level has now been well
documented.
- Mouse lemurs; Hafen et al. 1999,
- Japanese macaques, - high degrees of social affinity also produced
- Chimpanzees (Tanaka 2006) acoustically more similar calls independent of genetic
- Marmosets (Snowdon 1999), relatedness (Lemasson 2011).
- Campbell's monkeys (Lammasson ? neural circuits involved in the generation of vocal calls
2004; Ouattara 2009
in NHP are radically different from those involved in
human speech(Jürgens, 2002).

14. Language affixation
Cotton Top Tamerins can learn an
affixation pattern that shares
important information with our own
inflectional morphology
e.g. the rule that adds ‘-ed’ to
create the past tense
(Endress et al. 2009)

15. Method
‘shoy’ = affix
‘bi’, ‘ka’, ‘na’, ‘to’, ‘gu’ ,‘lo’, ‘ri’ and ‘nu’ = familiar stems
‘brain’, ‘breast’, ‘wasp’, ‘snake’ and ‘swan’ = test stems
1. Familiarised subjects to bisyllabic items
conforming to either a pre-fixation or suffixation
pattern they heard 14 words 70 times.
2. TEST ‘shoy’- ‘bi’ or TEST ‘ka’- ‘shoy’
a. Half the subjects tested on the pre-fixation pattern
and 29 days later the suffixation pattern
a. The other half tested suffixation pattern first and
33 days later the pre-fixation pattern

16. Results
The monkeys orientated more towards violations that
consistent conditions
Cotton Top Tamerins can learn a rule formally similar to
affixation patterns in humans
-suggest that this domain specific mechanism shared across
humans and NHP

17. Combinatorial signals
Human speech uses a rule-governed assemblage of
morphemes into more complex vocal expressions.
Loud alarm calls
Hack=
Pyows =
Putty nose
monkey
Arnold and Zuberbuhler
Playback
2004 experiments Pyow-Hack = ‘Group
progression’

18. Supporting theories
Innate Biological System

19. Evidence from gestures
Association of manual and
facial/vocal signals in groups of
chimpanzees and bonobos,
- 31 manual gestures
- 18 facial/vocal signals.
• Gestures seem less closely tied to
particular emotions, such as
aggression or affiliation,
• possess a more adaptable function
and likely under greater cortical
• Candidate modality to have acquired
control than facial/ vocal signals
symbolic meaning in early hominins?

20. Symbolic language
• Washoewas taught over 100
manual signs,3 based loosely
on American Sign Language
(ASL)
• Combine signs into two- or
three-‘‘word” sequences to
make simple requests (Gardner &
Gardner, 1969).
Kanzi –large vocabulary, based on pointing to symbols on a keyboard + gestures
-limited to only two or three ‘‘words”.
-follow instructions conveyed in spoken sentences with as many as seven or eight
words (Savage-Rumbaugh, Shanker, & Taylor, 1998).
-roughly equivalent to that of a 2½-year-old girl (Savage-Rumbaugh et al., 1998)

21. Supporting theories
Usage based system

22. Genetics
-KE family show no activation in Broca’s area while covertly
generating verbs (Liégeois et al., 2003). Point mutation in FOXP2
-FOXP2 gene in humans is involved in the cooption of vocal
control by Broca’s area (Corballis,2004a).
-Highly conserved in mammals,
FOXP2 gene underwent two mutations since the split
between hominid and chimpanzee lines.
- ‘‘some 10,000–100,000 years ago” (Enardet al., 2002) it not KE family
unreasonable to suppose that it coincided with the
emergence of Homo sapiens around 170,000 years ago.
-Recent evidence that the mutation is also present in the
DNA of a 45,000-year-old Neandertalfossil, suggesting that
is goes back at least 300,000– 400,000 years to the common
ancestor of humans and Neandertals(Krause et al., 2007).

23. Fossil Record
-Fossil evidence suggests that the anatomical requirements for
fully articulate speech were probably not complete until the
emergence of H. sapiens.
e.g. hypoglossal nerve (see image), which passes through this
canal and innervates the tongue, passes through the
hypoglossal canal, and this canal is much larger in humans than
in great apes, probably because of the important role of the
tongue in speech.
- Fossil evidence suggests that the size of the hypoglossal
canal in early australopithecines, and Homo habilis, was
within the range of that in modern great apes,
- the Neanderthal and early H. sapiens skulls was contained
well within the modern human range (Kay, Cartmill, & Barlow, 1998)

24. Summary
• Define language and its components
• Relationship to social learning
• Theories on how language evolved
• Empirical evidence from NHP research
• Evidence from genetics and the fossil record