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Signing With Gorillas:
Also see: "Animals and Signing"

In a message dated 8/23/2007 2:57:09 P.M. Pacific Daylight Time, an instructor writes:
Just out of curiosity, what is the average vocabulary for an adult ASL user?
How many signs does s/he know? A ballpark figure would be fine. I'm trying to compare vocabulary of human ASL-users with that of gorillas who have been taught ASL.
(name on file)
Professor of ____________, Charleston Southern University,
Charleston SC

Dear (name on file),
To answer the question "What is the average vocabulary for an adult ASL user" I will respond with a question.  "How many colors are there?"
Here are three sample answers to the question, "How many colors are there?"
1.  It is impossible to specify a certain number of colors exist.
2.  There are an infinite number of colors.
3.  It depends on which box of crayons you purchase.
4.  There are only three colors the rest are just combinations of those three.
Let's modify the question a bit:  "How many different colors can an artist create from a palate on which there are three globs of paint:  cyan, magenta, and yellow?" (subtractive)
Or how many colors can a computer screen depict by interpolating a combination of red, green, and blue dots?"  (additive)
If not "infinite" the answer is certainly a very, very large number. 
So, are there just three colors or are there millions?  The real answer is, it depends on how you look at it.
I fear that sometimes people look at "sign language" and all they see is "primary colors."
While it is tempting to announce that there are a "certain number of signs" or that an average deaf person knows a certain number of signs--doing so tends to vastly underestimate the "colorfulness" and power of the language. 
I once owned a paper-based dictionary of signs that contained 10,000 signs (20 years ago, published by the Oregon State School for the Deaf (Salem).  It was published as a set of two large binders.
So, are there 10,000 signs?  Does the average Deaf adult know 10,000 signs? 
I see online dictionaries pushing well beyond that number of signs. 
I suppose I personally know around 15,000 "base signs" and how to inflect (modify) most of those signs about five different ways, thus I know 75,000 "signs."  Note: Skilled signers know how to inflect their signs via in the speed and path of the movement, palm orientation, location, body posture, head tilts, facial expressions, etc. They can easily inflect the sign "tired" to mean "exhausted" or "strong" to mean "courageous." 
Have you taught the gorillas how to inflect their signs?  If we both know "X" number of signs and I know how to inflect my signs and the gorilla doesn't know how or at least not to the extent that I do, then I have a larger vocabulary than he does even though we know the same number of "signs."
Let's change topics for a moment.
Suppose we hand a small sharp knife to two different people.
Each knife has a relatively small, very sharp blade.
They are basically the same knife.
But the moment you hand that knife to two different people a profound change is likely to take place. 
For example in an average person's hands it remains a simple knife useful for hobbies, but in a surgeon's hands it becomes a scalpel.
What is the difference between a hobby-knife and a scalpel?  
The real difference is in the knowledge of the user. 
The average man can use a sharp blade to shave his chin or cut his food.  In the hands of a surgeon a knife can save lives and create seeming miracles.
We could set up a comparison and ask "What is the average number of knives a hobbyist owns compared with the average number of knives a surgeon owns?"
A huge pile of scalpels on a surgeon's tray really is quite meaningless since having more scalpels really doesn't affect the outcome.  It is the surgeon's knowledge and experience that affect the outcome.  The surgeon's knowing how and where to slice is what gives value to the knife.  If you needed a brain operation and had $100,000 to spend, which would be more valuable to you, a knife in the hands of a hobbyist, or in the hands of a surgeon?  What about a hundred knives in the hands of a hundred hobbyists vs paying for one skilled surgeon?
The comparison is amusing but doesn't help you as a patient. 
A knife in the hand of a hobbyist is not as valuable as one in the hand of a surgeon.  You are comparing two different values.  Knives to scalpels. Apples to oranges.  
Let's make the comparison even less valid.
Hand the knife to an ape.
You can hand knives to gorillas and you can teach them sign language and they will use the knives to dig for food and the signs to "communicate."
But to compare the number of signs a gorilla knows to the number of signs a human knows (even if they are the exact same signs) is like comparing the number of knives a gorilla has to the number of scalpels a surgeon has.  
You can "hand" the exact same vocabulary word to a gorilla and to a human.  In the "hands" of a human it becomes a scalpel that can be used to slice new meanings out of the air.  In the hands of a gorilla a signed vocabulary word remains just a "knife" -- useful for basic purposes, but the comparison is at not valid, and at best--amusing. 
But beyond being amusing, there is a danger.  Just as having a knife wielding monkey perform brain surgery would be dangerous--it is also dangerous for well meaning researchers to make superficial comparisons between the signing of humans and that of apes.  The two might seem the same but they are as different as a knife is from a scalpel--yet for the same reason: the user.
Apples to oranges.
Hmmm, better make that bananas.
(Dr. V of ASLU)
p.s. I'm NOT comparing you to a knife wielding monkey.  I'm sure YOU are one of the good researchers who will consider and reflect on the differences between human an primate signing as you develop your research.
In a message dated 8/24/2007 5:20:07 A.M. Pacific Daylight Time, an instructor writes:
Thanks so much for your quick reply. Actually, I teach people --- college students --- linguistics. One of our topics is animals and human language. For years, I've been intrigued by the work that Penny Patterson has done with Koko the gorilla. I've begun to suspect that Koko actually has the ability to use human language, but this ability is degraded, well below what a human can do (Koko's IQ, measured at 70, led me in this direction). Your e-mail adds a lot of support to my theory, since Koko's vocabulary, 6800 basic signs (with no evidence, that I know of, one way or another, of inflection), is well below what you reported. Thanks so much for your help.
(Name on file) 

Hello (Name on File),
I recall reading an interview that someone conducted with Koko. At one point the interviewer wrote that Koko had responded to a question by stating "I am the Devil."  The interviewer used this statement as basis for criticism of Koko.  I remember thinking, how pathetic, that interviewer doesn't realize that the sign "devil" can also be used to mean "mischievous."   It was obvious to me from the context of the question and her response that Koko was just simply admitting him that she was a "tease." Yet, because of his (or whatever trainer or interpreter was being used that day) unfamiliarity with the language, there was a egregious error in interpreting her meaning.
Good luck with your research.

One of Penny's post-docs presented a paper about Koko, "Phoneme Recognition in Mountain Gorillas". Basically, Koko's understanding of spoken English is phenomenal --- for an animal. If I duplicated the experiment with a human who had normal hearing but was forbidden to speak, s/he would run circles around Koko. More evidence that Koko truly has and can use human language but her ability is well below that of humans.
(Name on file)

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