Download Design features of language, animal communication systems

Animal communication
Overview
 Why study animal communication systems?
 Design features: human language vs. animal
communication systems
 Chimp studies: can chimps learn language?
 Evolution of language
 Summary: innateness unit
Why study animal communication systems?
Similarities, differences between animal, human systems
may help determine:
 Whether or not humans are unique, and if so,
 Which aspects of language are uniquely and definingly
human
1
Design features of language, animal
communication systems
Vocal-auditory channel
Does the system use only the VAC?
Human language: no:
 modality (= channel): vocal-auditory, visual-gestural
 written forms
Animal communication systems:
Mammals, birds: vocal auditory.
Crickets, rattlesnakes, woodpeckers: auditory but not
vocal.
Bees, stickleback (fish): Visual-gestural.
Moths: chemical.
2
Arbitrariness
Sign: represents a real world referent or concept
Are signs of the system arbitrary or iconic?
In human language, signs are not iconic. Possible
exception: onomatopoeia (sound symbolism).
But even onomatopoetic signs are arbitrary.
Variation across languages:
Imitating the sound of a sneeze:
English German Hebrew Arabic
[tu] [hti] [pti] [ts]
Japanese
[hk]
Variation within a single language (Witsuwit’en):
tlc'l ~ tltlts
tlquc ~ tlkw'akw
it (squirrel) is chattering.
it (frog) is croaking.
3
Arbitrariness not a unique characteristic of human
language.
 Responses of Vervet monkeys to 'eagle', 'leopard' and
'snake' predators (Figure 16.12)
 Seagulls indicate aggression by turning away from
opponent and pulling grass out of the ground
(Signs in animal communication systems can also be
iconic: e.g. Japanese macaque (Figure 16.3) opening
mouth and baring teeth to threaten.)
4
Cultural transmission (tradition)
Does a learner learn only from a more experienced user?
Humans: Critical Age cases like Genie: native speaker
input is crucial in first language acquisition.
Animals: Some aspects seem to be innate, some learned.
Innate aspects:
European cuckoo: Birds reared in isolation sing song of
species.
Bees: Austrian and Italian honeybees do different kinds of
dances (represent different honeybee “dialects”). (Italian
use sickle dance to represent intermediate-distance food
source; Austrian do not) Hybrids of Austrian and Italian
honeybees do dance of parent they most resemble
physically. Also, bee raised in isolation has no problem
doing dance.
Learned aspects:
Bullfinch: males can learn canary song
Some birds reared in isolation don't sing right (critical
period for song acquisition)
Cultural transmission of system not unique to humans.
5
Interchangeability
Can the sender and receiver roles be interchanged?
Humans: yes, but some male and female differences
possible. Witsuwit'en lexical differences:
-yez 'son, daughter (of woman)'
-ts 'daughter (of man)'
-yi 'son (of man)'
Interchangeability not unique to humans: many animal
communication systems have interchangeable roles.
Many animal communication systems don't have
interchangeability:
 Female vs. male differences in moth communication.
 Stickleback courtship dance done by males differs from
that done by females; neither can do the other's dance.
6
Semanticity
Do signs of the system convey meaning?
Semantic component of some morphemes in human
language:
past (tense)
‘yesterday’
[maja] (Sanskrit) ‘the mistaken belief that a sign is the
same as its referent’
Animal communication systems seem to express a more
limited range of meanings.
Displacement
Can the system be used to talk about things removed from
here and now?
Humans, yes. Animals, only in a limited way.
Bees can talk about sources of food that are not in
immediate environment (but only source of nectar just
visited, not one visited yesterday, or two trips earlier).
7
Creativity (productivity)
Can the system be used to talk about anything? Is it “fully
expressive”?
Human language: yes. Animal communication systems:
do not appear to be open-ended.
Bee dancing exhibits displacement, but how creative?
von Frisch: dish of sugar water placed on top of radio
beacon, positioned hive underneath the dish. Bees who
found the food did a round dance (nearby food source), but
couldn't indicate verticality.
8
Duality of patterning
Can patterns be found both below (phonology) and above
(morphology, syntax) the level of the sign (morpheme)?
Phonology: /k/, /æ/, /t/: /kæt/, /ækt/, /tæk/
Morphology: /tæk kæt/, /kæt tæk/
Animal communication systems appear to lack morphology
or syntax (although bird songs can be analyzed as
combinations of notes).
9
Structure-dependence
Is the system hierarchically organized?
Human language constituents: ambiguous phrases,
coordination, pronominalization, structure-dependent rules
(passivization, inversion in questions).
Hierarchical structure not found in animal communication
systems (as far as we know).
10
Summary---design features
human
languages
only use vocalauditory channel
arbitrariness of
symbols
cultural transmission
interchangeability
semanticity
displacement
creativity
duality of patterning
structure dependence
no
animal
communication
systems
no
yes
some
yes
yes
yes
yes
yes
yes
yes
to some extent
yes
more limited
not in most systems
no
no
no
11
Chimp studies
Hypothesis: Maybe chimps don’t use human language
because of lack of opportunity to learn it.
Chronology of studies
1931--Gua
1947---Viki
1966--Washoe
1966--Sarah
1974--Nim Chimsky
1977--Lana, Sherman, Austin (chimps). Kanzi (pygmy
chimp)
1981--Koko, Michael (gorillas)
1983--Chantek (orangutan)
...
Washoe and friends can be viewed at CWU
“Chimposiums”: (509) 963-2244 ($10)
12
Problems with some of the studies
 Inherent bias of researchers
strong desire to believe in success of subjects
 Clever Hans phenomenon
dressage: tested may pick up on unintended cues of
testers
double-blind experiments
13
Summary of chimps' accomplishments
 Can learn to associate referents with arbitrary signs
 Can learn to use signs spontaneously
 Can learn to use signs creatively
Washoe: 'water bird' (for swan)
Moja (chimp):
'listen drink' (for Alka seltzer in a glass)
'Metal hot' (for a cigarette lighter)
'metal cup drink coffee' (for a thermos bottle)
'dirty good' (for a potty chair)
Lucy:
'smell fruits' (for citrus fruits)
'cry fruit' or 'hurt fruit' (for radish)
'drink fruit' or 'candy fruit' (for watermelon)
 Can invent totally new signs
Washoe invented a sign for 'bibs'
Lucy invented a sign for a leash used to walk her along a
busy highway.
14
 Can come up with creative solutions to problems.
Kanzi
When friend Austin the chimp was moved out of
compound, Kanzi got lonely, typed 'Austin TV' to request
videotape of Austin.
 Limited acquisition of syntax (2-3 sign utterances)
Washoe: inconsistent word order
Sarah: comprehended commands like:
‘Sarah cracker candy yellow dish cracker blue pail insert':
[[Sarah] [[[cracker candy] [yellow dish]] [[cracker] [blue
pail]]] insert]
15
Chimps vs. children
How do chimps’, children’s accomplishments compare?
(Is chimp language creative, rule governed, as children's
emerging language is?)
 Similarities:
 One-word, multi-word stages similar
 Creativity (e.g. Washoe's 'water bird') in both
systems
 Differences:
 Most advanced of chimps reported have syntactic
and lexical skills most comparable to those of a 1-2year old child.
16
Language evolution
 How did language develop/evolve?
 Did language evolve by accident or by adaptation?
Some features of humans (as compared to other
hominoids):
 walking on two feet, leaving hands free for tool use
 increase in size and cognitive capacity of brain
 changes in shape of vocal tract
17
Increase in brain size
The more complex the animal, the larger its brain.
The longer a species is on the planet, the bigger it gets.
Earliest hominoids, modern chimps:
Modern human:
400 cc
1360 cc
Why increase in brain size?
Hypothesis: greater intelligence needed to deal with social
complexity.
18
Changes in shape of vocal tract
"Ontogeny [development] recapitulates phylogeny [history
of species]".
Some features of vocal tract in newborn humans, other
primates:
 Larynx and epiglottis are higher. Therefore:
 Airway is more efficient for breathing.
 Larynx and epiglottis help create a tube from lungs to
nose, permitting simultaneous breathing, eating. (Adult
human vocal tract more hazardous for swallowing.
Larynx must be pushed out of way by muscles of vocal
tract.)
Why descent of larynx (if this leads to increased danger of
choking, less efficient breathing?)
/i a u/: 2-tube vocal tract of adult humans can produce
vowels
Language apparently of higher survival value to species
than safe breathing.
Summary: Innateness?
Are humans genetically predisposed to learn language?
19
 Language universals
 can be identified
 why do they exist? (processing limitations or procssing
enhancement?)
 Developmental evidence
 universality and universal characteristics of first
language acquisition
 creolization
 Neurolinguistic evidence
lateralization (hemispheric specialization)
 Animal systems, accomplishments of chimps
Only human language exhibits creativity, duality of
patterning, structure dependence
 Evolutionary evidence
lowered larynx enhanced vocalization at expense of safe
breathing
20