Transcript Quick Write - Bases Produced

Communication and Language,
try #3: Monkey See, Monkey Do?
September 17, 2012
Questions
1. What’s the difference between language and
communication?
2. How do we know that animals don’t have language?
3. Can animals acquire language if we try to teach it to
them?
More Design Features!
• In my efforts to simplify the presentation of the design
features of language, these are the ones I left out:
13. Feedback: users of a language can perceive what
they are transmitting and can make corrections if they
make errors.
14. Rapid Fading: Message does not linger in time or
space after production.
15. Specialization: the direct-energetic consequences of
linguistic signals are usually biologically trivial; only the
triggering effects are important.
•
But remember: the crucial design features for human
language are productivity, displacement and duality of
patterning.
The Bees
• Honeybees have one of the most complex systems of
communication found in the animal world.
• They “dance” to indicate the presence of food
sources in the vicinity of their hives.
• The dances take one of three forms:
• 1. Round Dance
• For food sources up to 20 feet away.
• Intensity indicates quality of source.
The Bees, part 2
2. The Sickle Dance
• Food source from 20 to 60 feet away.
• Intensity indicates quality of source.
• Angle with vertical represents angle of source with
respect to sun.
The Bees, part 3
• The Tail-Wagging Dance
• For food sources more than 60 feet away.
• Also indicates quality and direction
• Slower rate of repetition = longer distance
Bees dancing on the web
• http://www.pbs.org/wgbh/nova/bees/dances.html
• You be the bee:
http://www.pbs.org/wgbh/nova/bees/dancesbees1.html
• Is the bees’ form of communication language?
• Which of the “design features” does it exhibit?
What About Dolphins?
• Many people consider dolphins to be highly intelligent.
• Easily trainable
• Proportionally large brain mass
• Q: How much can they communicate with each other?
• They use clicks for sonar…
• Squawks and whistles signal emotional states.
• Bastian (1971) tested dolphins’ communication abilities in
a clever experiment…
The Dolphin Experiment
• A male dolphin and a female dolphin were placed in
separate tanks.
• Each tank was equipped with two different paddles
that the dolphins could push.
• And an intercom system…
• Female dolphin was shown either a flashing light or a
continuous light (which the male couldn’t see).
• Female was supposed to:
• Push the right paddle for continuous light
• Push the left paddle for flashing light
• And tell the male dolphin to do the same…
The Dolphin Experiment
• If both male and female dolphins pushed the correct
paddles…
• They both got a fish!
• What happened?
• At first it looked like the dolphins were communicating.
• But then the researchers tried the same experiment:
• when the male could see the lights, too
• and also without the male in other tank.
• The female kept making the same calls.
• Conclusion: she wasn’t trying to communicate…
• She just wanted to get the fish.
Clever Hans
• One consistent problem with animal communication
research is that there is often a temptation to overstate
the animals’ abilities.
• A classic example: Clever Hans.
• Clever Hans was a
horse who lived in
Germany around
1900…
• And was taught to
answer math
questions by tapping
his foot.
The Clever Hans Effect
• Clever Hans was eventually subjected to scientific
scrutiny.
• Finding #1: Hans had more difficulty when he couldn’t
see the person asking the question.
• Finding #2: He also had difficulty when the questioner
did not know the answer to the question.
• His accuracy dropped from 89% to 0% correct.
• Conclusion: the questioners were (subconsciously)
tipping the horse off.
• Hans was just very talented at reading their change
in posture when he made the right number of taps.
Alex the Parrot
• Another celebrated animal--from recent times--is Alex,
the grey parrot.
• Alex was said to know 100+ words,
• could answer different questions about the same
object
• and make categorical distinctions.
• Check out a video:
• http://www.youtube.com/watch?v=R6KvPN_Wt8I
• Q: Had Alex acquired language?
Conclusions (for now)
• Animals are capable of lots of amazing things…
• but language is not one of them.
• Animals’ native systems of communication do not exhibit
all of the design features of human language. In particular:
• Displacement
• Creativity
• Duality of patterning
• Attempts to teach language to (non-primate) animals have
met with little success.
• However, teaching language to primates has yielded
some intriguing (and controversial) results…
Some Intellectual History
• During the middle part of the twentieth century, the
school of behaviorism reigned supreme in psychological
circles.
• Chief advocate: B.F. Skinner (1904 - 1990)
• The study of behaviorism focused on how behavior can
be shaped by environmental forces.
• A big idea: operant
conditioning.
• = Desired behaviors can
be brought out in an
organism in small steps,
through rewards.
• Language = “Verbal Behavior”
The Linguist Strikes Back
• Noam Chomsky (1928 - ) published a scathing criticism
(1959) of Skinner’s work on “verbal behavior”.
• Some of Chomsky’s main criticisms:
• Kids learn language with or without reinforcement.
• Language use is not necessarily
functional.
• Language involves creativity.
• not derived from external
influences.
• we’re constantly processing new
linguistic forms
•  Language is innate.
Evidence?
• An example of non-functional language use?
“Each Nutch in a Nitch knows that some other Nutch
Would like to move into his Nitch very much.
So each Nutch in a Nitch has to watch that small Nitch
Or Nutches who haven’t got Nitches will snitch.”
--Dr. Seuss
• Regarding language acquisition:
“We are designed to walk...That we are taught to walk is
impossible. And pretty much the same is true of
language. Nobody is taught language. In fact, you can’t
prevent the child from learning it.” --Noam Chomsky
The Great Debate
• The Skinner/Chomsky debate inspired scientists to
determine if animals could be taught language, using
behaviorist principles.
• Early attempts had met with little success.
• Ex: Gua (chimpanzee, 1930s)
• raised alongside a human baby, in a human family.
• At 16 months, could understand 100+ words
• (more than the child)
• However: she never improved after that…
• And she never understood word order (syntax).
The Great Debate
• A similar experiment with the chimp Viki (1948) was also
disappointing.
• This time, her handlers tried to directly train her how to
speak.
• She only learned how to produce a few words:
• mama, papa, cup, up….
• and only with great difficulty.
• Fundamental problem: the vocal tracts of chimps prevent
them from making the same speech sounds we can.
Vocal Tract Anatomy
• Our vocal tracts are shaped in a way that makes it easier
to speak…
• But more dangerous to eat!
Washoe
• In 1965, Allen and Beatrice Gardner started teaching
sign language (ASL) to a chimp named Washoe.
• This worked out much better.
• Wahoe was taught to use
signs deliberately, in a signing
environment.
• Acquired ~85 signs in four
years…
• and used combinations of
signs:
• BABY MINE, YOU DRINK
• creativity: WATER BIRD
Koko
• Maybe the most famous signing primate is Koko, the
gorilla.
• Koko began to learn ASL in 1972 (and is still going!)
• Has reportedly acquired as many as 2,000 signs.
• Has exhibited some creativity:
• used FINGER BRACELET
for “ring”
• once referred to trainer
Francine Patterson as a
DIRTY TOILET DEVIL
Really?
• Francine Patterson has made some unusual claims
about Koko’s abilities.
1. Koko “rhymes” signs like BEAR and HAIR
• (even though the signs are not visually similar)
2. Koko substitutes homophones like EYE and I, and
KNOW for NO.
• (again, without similarity between the signs)
• Linguists remain skeptical about Koko’s abilities.
Non-Signing Experiments
• Some chimps have been taught to communicate using
arbitrary symbols.
• “lexigrams”
• Sarah: manipulated plastic symbols on a board.
Sarah
• Sarah supposedly understood 130 different symbols.
• including abritrary and abstract concepts.
• E.g., Sarah could make sense of the following:
Nim Chimpsky
• Nim Chimpsky was a chimp who was also taught sign
language.
• Learned through interacting with experimenters.
• Was named to annoy Noam Chomsky.
• Learned 125 signs in about
four years.
• Used combinations of
signs…
• some longer than two
words.
The Trouble with Nim
• Re-analysis of the Nim data showed:
• Nim did not sign spontaneously.
• Nim did not respect turn-taking in conversation.
• 39% of Nim’s “utterances” were repetitions of what had
just been signed (vs. 18% in children).
• Sequences of 3 and 4 signs did not add new
information.
• 71% of Nim’s utterances were interruptions.
• Nim typically used signs to get rewards, not to convey
new information.
Typical Sentences from Nim
• Nim eat Nim eat.
• Drink eat me Nim.
• Me gum me gum.
• Tickle me Nim play.
• Me eat me eat.
• Me banana you banana me you give.
• You me banana me banana you.
• Banana me me me eat.
“Animals can be repetitious to the point of inanity.”
--E.O. Wilson
Current Work with Bonobos
• After Nim Chimpsky, funding for primate language
studies mostly dried up.
• …although a few experiments went on.
• One project involves bonobos, a sub-species of
chimpanzees.
• Bonobos Sherman and
Austin have also been
trained to use lexigrams.
• Kanzi learned just by
watching Sherman and
Austin’s training!
Bonobo Successes
• It is claimed that bonobos:
• Have better comprehension abilities than production
abilities.
• (just like human children)
• Learned to comprehend just through ordinary exposure
(Kanzi)
• Skills include creative extension of signs for humor and
metaphorical expression.
• Evidence of displacement
• (referring to chimps who are not present)
Bonobo Criticisms
• Kanzi’s use of symbols for purposes other than requesting
is only 4%.
• Longest “utterances” are three signs, with variable word
order.
• For all chimps who are taught language, development
reaches a modest level of success and then stops.
• In children, development keeps going well beyond the
early years of life.
In Conclusion
• The ability of animals to acquire language is limited.
• Works best with primates.
• Generally requires focused training conditions.
• Primate “language” can exhibit some crucial design
features like creativity and displacement…
• However, it also exhibits features not found in human
language.
• It also fails to exhibit other important features like
consistent word order, continual progress, etc.
Moral of the Story
• Ever since Chomksy’s insight into the biological nature of
language,
• Scientists are much more open to the idea that
behavior can be biologically specified.
• Think of the human use of language in the same way that
you think of:
• Spiders spinning webs
• Eagles flying
• Ducks swimming on water
• etc.