Chimpanzee “Language”

Psych 1090

Lecture 13

The issue of whether animals can truly communicate with

humans is incredibly thorny….

The fights pro and con were brutal and, in a sense, doomed

the fieldHowever, before it collapsed, the work had a stunning impact not only on how we view animals,

but also on our understanding of language

And I’m going to try to give you just a taste of what happened

The work started with the Kelloggs

who brought up a chimp, Gua, along with their son, Donald….

and who showed that simple exposure to language wasn’t enough to engender it in a

nonhuman primate

Hayes and Nissen came next; they trained a chimpanzee named

Viki…Although Viki succeeded on a large

number of cognitive tasks,

she acquired only a very few English labels;

Was her failure due to her ‘primitive’ vocal tract or her

cognitive skills?

The Gardners, Allan and Trixie, watched tapes of Gua and Viki

and realized that they could understand everything without

soundi.e., that the apes used a lot of

gesturesThey reasoned that maybe one

could use ASL, the language of the deaf, to work with the apes

They reasoned that ASL would allow them to separate out issues

ofthe inability to produce labels

vocally

from the possibility of learning a human language

Note that, at the time, not everyone agreed that ASL was a

true language

Some folks looked at ASL as a proto-language;

others thought about it in terms of a rationale for a gestural

theory for the origins of human language

and others began studying ASL for the first time in great detail as

a consequence of the ape ‘language’ controversy

Were what seemed to be simple signals like “you-me-eat?”

representative of a real language, whether produced by humans or

apesor were such utterances as

primitive as they at first appeared?

Until the ape studies, no one seemed to care very much

But those issues were to come…First the Gardners started their pioneering work with Washoe

Not too long afterwards, David Premack decided to work with a

more restrictive symbol system of plastic chips…

He trained Sarah to use these chips to communicate with her trainers

Sarah with something like “apple same as

apple”

And fairly soon after that, Duane Rumbaugh, working with von

Glasersfeld and others

developed a computer-based system of lexigrams that allowed

their ape, Lana

To function without any human intervention at all, to avoid cuing

Original lexigrams were color-coded….

                                   

          One of the later keyboards

And, in another lab at Columbia University, Herb Terrace started a second ASL project with Nim

Chimpsky

Terrace had been trained by Skinner and felt that language

could be taught through operant conditioning;

Nim did not learn as much as Washoe,

And Terrace’s attacks on the field pretty much brought it

down

But, again, that was in the future and an incredible amount of

information was gathered in the interim

The basic issue—how did animal “language” differ from human

language

could only be resolved if we could figure out the limits of the

animal’s abilities…

AND insure that any animal failure was not a consequence of poor training or vocal anatomy

So, that is why I’m going to start with Premack’s 1990

paper even though it’s not the oldest

Because he brings up fundamental issues of similarities and

differences Between animals’ and humans’

use of symbols…

Are they equivalently words?

Now, Premack was not the first to worry about concept “word”

In 1960, Quine wrote a paper on the topic…he proposed the

following:A linguist visits a primitive tribe, and while he is talking to a tribal member, a fuzzy creature runs

across their path

The tribal member states “Gavagai”….

Our inclination is to assume that “gavagai” is the label for that

creature in that culture

But, in reality, gavagai could mean any furry critter, anything that is running fast, a generic term for a

mammal…Or even lunch!

Or, of course, any number of different things….

The point was to make it clear that establishing the referent of a sound pattern isn’t necessarily

simple…

And that we do it by context, by exclusion, by category…etc.

Now, if we have so much confusion about what a word

is or means for humans,

there is even more confusion about what it might mean for an

apeand whether an ape would be mapping human terms onto

something already existent in ape terms

Specifically, when we train an animal to label something,

are we first having to train it to understand the concept of

labeling?

Or are we just setting up some kind of paired association that

has no linguistic function?

These are not trivial questions, and fueled the

sometimes vitriolic debates

And there aren’t any clear, clean-cut answers

Although, as we’ll see, Premack’s animals seemed to

treat their plastic chips as words…

an intriguing study by Lenneberg suggested maybe

not…Lenneberg replicated Premack’s chip study with college students,

who, not surprisingly, did extremely well on the tasks..

BUT, at the end, had no idea they had learned a ‘language’

So you need to keep this all in mind as we discuss the various papers and the various results

Remember, all of these apes were trained in very different

ways, with different techniques

And even Nim and Washoe, both taught ASL, had strikingly different

input

So let’s go back to part of Premack’s paper…about

halfway through, where he starts talking about Sarah’s

learning….After she had acquired a number

of labels, she began to learn more rapidly…

and, in fact, connected ‘words’ and objects just by having them placed

together

And, interestingly, we see this difference in our birds…

The first label is learned quickly, as a generalized ‘gimme’

The second and a few subsequent ones are learned

very slowly, Suggesting that the concept of

labeling is what is being learned

And then the animals ‘get it’…

although naming and requesting are still not separated

In fact, this separation is what caused many researchers to use nonreferential food rewards….

The animal supposedly would see the treat as a reward for naming in

general

But that didn’t happen…animals trained with nonreferential

rewards never really understood labels

They just learned associations that gave them treats without

connecting the label and the object as a name

The animals couldn’t usually transfer the label to a similar but

not identical item

So Premack could show that his animals treated the plastic chips the way children treated vocal

labels

The real question, still not totally answered, is what the chips—or

labels—represent to the ape

Let me try to clarify…

If I say “unicorn” to you,

You know exactly what I mean ….

Because you have a full mental representation of the unicorn, even if you had never seen a

picture and I said it was a “horse with a horn”

But if you needed an association between a label and a physical object in order to represent it….

You might not be able to understand what I meant…

And that’s what we can’t quite separate out for the animals

When is it just a Pavlovian association, like with a lemon and

salivating, for you and the animals…

or something more??

Does real reference require, as Premack suggests, some kind of

theory of mind?

That is, by using the label “apple”, Sarah theorizes that you have the same mental representation that

she has?

Tis not at all clear, and has been the basis for plenty of controversy

Because simple systems can be simple associations without

requiring clear representations

That is why Premack used the tests with things like apple stems, to see if these items engendered the same response as his plastic

chipsThe data suggest that the chips

may really have been representational

Another intriguing issue that Premack raises is whether

language training changes how apes think

In a sense, any training changes how thinking occurs….

That’s why programs to train students for SATs, MCATs, etc. are

so popular….

If you “teach to the test”, most students—human or nonhuman—

will do better on that test…

But they may not do so well on other types of intelligence test….

So there is a difference between practice effects and true re-training

And, again, that was one of the problems with Premack’s studies

If Sarah finally abstracts the chip that means “color of”

And learns brown through a statement “brown color of

chocolate”

The test of “brown” must be strong

But Sarah was given a brown exemplar along with three other already KNOWN color samples

So when tested on “take brown”

She might still have chosen merely on exclusion… “I know it

isn’t red, green, or yellow”…

So she would need to choose from a pile that also had purple and

silver…

And, of course, we run into the same issues of “grammar” as we

did with Herman’s dolphins….

Is it just rule-governed behavior, which isn’t exactly grammar?

So, for example, Premack’s apes did fine with their usually VERTICAL language with things

like “red over blue”

But had a terrible time with things like “red under blue”

The latter was opposite to the ordering of the chips on the

board

Such data presume rule-governed behavior, not grammar….

So, keep all this in mind when reading about the language-

trained apes that succeeded on certain tasks

And the nonlanguage-trained apes that failed…

The task with the cut-up fruits and the tubes of water is a good

example….

Nonlanguge-trained apes knew match-to-sample…

And matches were always identical….

So faced with apples and tubes of water…

It wasn’t all that surprising that they were at chance….

They had no idea that they were matching proportions….

Only identity, and nothing was an identity

The language-trained apes knew match-to-sample…

But also had lots of training where they matched objects to

chips

So they understood that the objects didn’t have to have an

exact match to be correct

To them, the partially-filled tube did not have to have the same representation as a plastic chip

What the language-trained ape knew was to derive information

from such situations

So it could respond based on the concept of ‘quarter-ness’

In a way that the nonlanguage-trained ape could not….

But language per se was not necessarily the difference

Only the way the animal had been trained to respond to

certain situations…

The same issue probably held with the causality tests…i.e.,

knife with cut item…

It wasn’t necessarily that the nonlanguage-trained apes couldn’t

understand the causality

They didn’t know how to express what they might have

known

The analogies test are my favorite

because these really ARE a lot like the kinds of tests given in

SATs

And for which training clearly makes a huge difference in

humans…

Why not in apes?

Sarah would see

?

Choice of the correct alternative might be done

The trials were a bit different for the nonlanguage-trained

apes

just by matching the most number of attributes

They saw something like

????

Tis not exactly sure that I would immediately understand,

if I were an ape and not an adult human

that I should pick the matching pair

So I’m not sure that Premack’stests were entirely fair

Now, it may seem that I’m really coming down hard on Premack

And I’m not really….

I do think that his animals learned to reason in a very

advanced way

I’m just not sure they learned language

So what about an ape like Washoe,

who was not trained in an operant paradigm but rather like

a child?Well, one problem was that at

the beginning the Gardners were not fluent in sign…

So Washoe wasn’t really taught ASL

But rather a form of signed English

which was neither ASL nor English

Nevertheless, Washoe did learn a lot about the referent of each sign

A critical issue was that there were no formal drills like those of Sarah

And that Washoe had constant referential experience with all

her signs

Later, younger apes were taught by fluent ASL people

And thus these apes really were exposed to a human language

And, one of the major issues concerning this work is that ASL

does not have the same grammar as English…

So, as I noted earlier, apes that signed “you-me-eat?”

were compared to young speaking children who might say

“Mommy, lunch now?”

Or even older children who might be using full English

sentences…If, however, the apes were compared to ASL proficient

children,

The parallels were much stronger

Even repetitions used for emphasis were similar

But much argument centered on even whether Washoe’s labels

were indeed referential…

Did the ASL sign for shoe actually refer to shoes in general and not

to anything on a foot, for example?

And if the latter, was it clever metaphor or an error???

Of real import was the Gardner’s descriptions on their vocabulary tests of getting the subjects to

cooperate…

Think about trying to get a somewhat hyperactive child to sit still through a repetitive test

And you start to see their problems

Unlike the dolphins, the apes were not given their daily rations as part of the test

Mainly because hungry apes are even more difficult to get to

focus

These issues were not trivial because most critics had

worked with pigeons or rats

Or with children who were cooperative;

In most studies, ‘fussy’ children are eliminated from testing

And, overall, the apes did respond appropriately to most of the exemplars in the vocabulary

test

Interestingly, many of the errors were small errors with respect to where a sign was placed or the

action that was used…

Placing several fingers to the nose meant FLOWER and one

finger meant BUG…

In context, such errors could be made by humans and be ignored

These errors are the equivalent of mucking up small phonemes

in English

Other errors were within category… COMB for BRUSH

Objects that might be linked closely in memory

The Gardners had other data for referential sign use…

There are videos via hidden cameras of the younger chimps

correctly signing about the pictures in magazines they are

viewing

Or their asking for objects that were lost

The Gardners emphasized the strong need for interaction with

their subjects

arguing that communication is, by its very nature, interactive

and similarly emphasized the need for referential rewards

Their initial papers, published in 1969, strongly influenced some

researchers like myself and Reiss

And their work strongly contrasted with that of Terrace--

who also used sign, but in a very different manner

Terrace’s ape, Nim, would often be taught signs in the

absence of a referent

under the assumption that the referent would be distracting and

make learning more difficult

So, in many cases, only after a sign was acquired did the referent

appear

Not surprisingly, Nim didn’t understand why he was supposed

to make these signs….

and the occasional food reward just acted to confound the label to be learned with the food reward

He did eventually learn a number of signs

And initially, Terrace claimed full reference…which he later

retracted

He argued in particular that not only Nim, but all apes failed in

putting the labels into sentences

And that therefore they really hadn’t learned very much at all

Interestingly, when Terrace’s students did interact with Nim on

a less formal level

labeling actions and objects

they didn’t do it in a systematic way, so Nim was stuck with ‘gavagai’ like situations…

“Up” might be used when he was lifted to his high chair, but not when he was lifted in other circumstances

leading to lots of confusion as to the meaning of labels

The Gardners, in contrast, were very good about using a label in a number of contexts so meaning

could be abstracted

Now, as you may have noted, the Gardners take a hit at

Terrace in their article

mainly about experimental design

Because Terrace had published an article in Science a few years

earlier that had completely trashed

them

Terrace had taken some of the Gardners’ video and done a

frame-by-frame analysis

which isn’t exactly fair for a fluid language like ASL

And argued that Washoe really didn’t respond to questions but

just repeated her trainers

The arguments were unfounded, but led the

Gardners to lose funding and close their lab

Remember that ASL has a different grammar from English; sometimes where in space a sign

is placed is critical

And lots of arguments ensued

The Gardners gave their apes to their student, Roger Fouts, who had space and funding in

Oklahoma

And, as expected, continued to collaborate

Even after the apes were moved to Washington State

The Gardners were particularly interested in how the apes used

their signs interactively

because that was one of Terrace’s real arguments…hence

the 2000 report…

tho’ not clear when it was performed

As you can see from the transcripts, some of the

material was a true dialogue

Other transcripts were a bit surreal

Some of the criticisms, however, would also be leveled at young

human signers

Specifically, issues of emphasis and repetition, or motivation for a particular

itemor, in particular, interest in

something other than what the experimenter was targeting

The latter could really mess up their trials, suggesting the apes weren’t understanding the signs

Often times the apes would stick to the original topic despite the experimenter changing the subject…

That seemed particularly common when the ape was signing about food and the experimenter ignored what could have been a request

But even if the topic was not food, if the experimenter

stuck on topic

the ape was more likely to stick as well…

Sometimes expanding the utterance…but often just

copying it…

However, some of the copies were meaningful for

emphasis…

Or, when just one more sign was added, the ape was—

because it was ASL, not English—

actually requesting something of the experimenter

And one has to wonder at what the apes thought about

the non-sequitor type interactions…

Did the apes think that the humans were weirdly off-topic and should be brought around?

We can’t immediately fault the animals for their actions

Of course, even when the experimenter was ‘on topic’,

it isn’t clear as to what is happening…

Nevertheless, the apes are responding in a statistically

valid manner

IF you compare them with young signing children….

And that was really one of the major issues …

There were also ASL projects with an orangutan (Lyn Miles) and a gorilla (Penny Patterson)

but none of their data were ever published in peer-reviewed

journals

which is why we aren’t examining their material

The other major players in the ape language debate were the

Rumbaughs

As mentioned earlier, they first worked with Lana, lexigrams, and

a computer

and Lana had almost no social interaction with humans

The idea was that she could not be cued in any way by

humans

And that her data would be collected by a computer 24/7

therefore be totally above reproach

Note that she did learn to use the lexigrams in a standard

manner to request food, drinks, movies…

And their ideas about keeping humans out of the picture

didn’t quite work out….

video

She even learned to “erase” a sentence given to her that

didn’t make sense….

That is, the machine could “give” food but “made”

movies….

and she’d detect the incorrect use of a verb

So Lana had really, really good production….

And, because in children, comprehension usually precedes production, Rumbaugh assumed

that Lana comprehended her labels

But that was a real mistake…

When given a lexigram and asked to choose the item to which it

referred, she was often at chance

Suggesting that she had learned particular patterns that got her

what she wanted

but only in the particular context in which it had been trained

They taught their second apes, Sherman and Austin, quite

differently in order to avoid such problems

These apes interacted more with each other than their trainers

although they were also taught with lexigrams

And the Rumbaughs stopped color coding the lexigrams as cues

Sherman and Austin did acquire a lot more reference, but in their case much of it was in context

So they understood that a “key” was something to open a box,

but had some trouble identifying it as a sole object

simply because that was the way they were trained

There are a large number of studies with these two apes

All of which are fascinating but we don’t have time to go

through them….

One issue of interest was that although the experimenters

talked with these apes,

the Rumbaugh’s claimed they didn’t understand English

Now, privately, Boysen disputed this issue, and Fouts had shown that other apes could associate

ASL signs and English

Given how many animals do understand human speech, one would expect apes to be among

them

Interestingly, data show that chinchillas and even quail

actually parse sounds just as humans….

that is, they exhibit categorical perception

Such that sounds like /p/ and /b/ have distinct cut offs in VOT and

don’t blend into one another

So, if nothing else, chimps are likely to have the hearing and

the neurological underpinnings

to be able to distinguish what we call ‘minimal pairs’

“pea/tea”, “cork/corn”

About this time, the Rumbaughs decided to try to work with a

pygmy chimp

Under the assumption that the pygmy chimps might by even

more closely related to humans

And thus more likely to acquire language-like behavior

They started with an adult, Matata, who was still caring for

her infant, Kanzi

Despite many, many months of instruction, Matata didn’t get

very far in using the lexigrams

But Kanzi, who had been watching most of his mother’s training

in a way reminiscent of our using two humans to train Alex,

Actually began to pick up quite a bit of understanding about what

the symbols meant

video

video

He even did fairly well with complicated sentences,

Even when novel and somewhat nonsensical,

whether with lexigrams or in English

Now, of course, Kanzi was far better than Sherman and

Austin

But was it because of his species or his training?

So the Rumbaughs decided to raise a pygmy chimp and a

regular one together so training wouldn’t be an issue…

Of course, the Rumbaughs could not know if there were any

individual differences in these apes….

Supposedly the apes were chosen with respect to birth-dates alone

But that doesn’t totally exclude such differences

And, of course, although they claim that the animals were

treated equivalently,

obviously every trainer knew which ape was which….

as well as the expectations of the Rumbaughs about the bonobos…

There are plenty of studies with humans suggesting that children will live up to

expectations…whether good or bad…

Substitute teachers were told that the same class was either exceptionally bright or slow…

And students met both criteria

If you look at the transcripts, both apes seem to be

functioning at similar, if not equivalent, levels

And, of course, we don’t know if what was chosen was truly

representative of the sessions

And, yes, I’m being quite critical

It’s very clear from the reported material that the apes were

treated somewhat differently;

were the caretakers truly responding to the levels of the

apes?

Differences could also be in how well the subjects attended…

And that could be a species OR an individual difference….

We really can’t know with only two subjects…

The arguments about differences in frontal lobes are compelling…

particularly with respect to keeping a string of labels in

mind…

But dolphins do just that, and an ape that makes a termite poking tool or eating certain

nettles has to have memory for various

steps

So I’m not sure that I buy into that explanation

It would be very interesting to see if the bonobos and chimps

have different MNs…

Of interest, too, is that in terms of production,

Both species of ape engaged in very non-ape like pointing and

eye contact

which suggests that avoidance of eye contact might be learned

or, obviously, at least unlearned…

And that pointing can be easily acquired in a fully enculturated

ape

And, again, the differences in production could be species-

related or not

Did the chimpanzee figure that what she had was good enough

(like my youngest parrot)…

so that it wasn’t really worth bothering to learn the additional

lexigrams?

Could be, given that she was slightly the junior

The really critical issue was that both species were given what we would call immersive input or full

enculturation

And that their development far outpaced that of Sherman and Austin who had not had such

input

or that of Lana…

Taken together, these studies suggest that whatever

communication skills apes do achieve

they, like children, need an interactive environment that

includes

reference, functionality, and socialization

So, the next question is why most of these studies have ended…

not only did the ape language work force us to examine the competencies of nonhumans

but it also forced us to examine human language more closely

Because if linguists are insisting that human language is unique

we have to understand what differentiates it from that of

nonhumans…

Not just argue that language is whatever it is that apes can’t

achieve

The bottom-line issue was that all these studies were first

attemptsAnd the glare of publicity made sure that any errors were blown

out of proportion

because many humans didn’t want to accept that an ape could

indeed communicate with humans

We now look at the work with the knowledge of all the

incredible things that animals can indeed do

And maybe wonder at the fuss…

But few of the studies we’ve read had yet been done, and animals were not considered capable of

much

So claiming language-like abilities, even if quite primitive

was more than most scientists could bear…

Just witness the current flap over the starling ‘grammar’ at present

to get an idea of what was happening in the 1970s and

1980s!

Briefly, Chomsky, Hauser and Fitch have argued that what

makes human language unique is recursion…..

being able to parse and understand embedded phrases

“This is the cat that ate the rat that lived in the house that Jack

built”

So they exposed tamarins to different types of grammars…

Some heard sets that were “ABAB” and others heard sets

that were “AABB”

Something like “put book take key” versus “put book key pail”

Note that the tamarins weren’t given anything meaningful like

verbs and nouns

Just various syllables produced either in male or female voices

And they weren’t specifically trained, just exposed to the

sounds

Then they tested whether the tamarins could detect violations

of the familiar grammars…

Those exposed to ABAB detected when they were given AABB

instead

But those exposed to AABB did not respond to ABAB as a violation

Humans, given the same nonsense syllables did catch the

differences

So the argument was that these orderings were representative of

a recursive grammar

And that a nonhuman primate failed to understand recursion,

and hence the language ‘difference’

Last week, a paper came out on starlings, who were trained to

recognize either of these grammars….

And, interestingly, the experimenters used notes from

their learned songs

“rattle” and “warble” motifs, not random syllables

They didn’t learn very quickly, but once they did

learn

It didn’t matter what they had learned; they distinguished it

from the other grammar

And easily transferred to new collections of rattles and whistles

So, did they succeed because birds need to be able to recognize vocal patterns

or because they were trained over thousand of trials and their exemplars were natural?

We won’t know til the relevant experiments are done

But that doesn’t stop the debate that this paper has

engendered in the literature

And that is not a bad thing…

Bringing up all sorts of alternative possibilities that must be examined serves to

clarify the experimental design

So…do animals have language?

Most have their OWN language which we are mostly

too stupid to decipher…

And some species can map what we teach them onto what they

have

To learn some elements of ours