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Keeping the Peace

Chimp Manners

Monkey See, Monkey Do?

Chimps Count

Finger Food

The Mating Game
in the classroom


Chimpanzees doing fractions? Language and math skills have long been thought to be solely human abilities, but an Ohio State University researcher has taught some chimpanzees to solve simple arithmetic problems. Primatologist Sally Boysen, who has been working with chimpanzees for many years, shows that the chimps are truly processing the information and not just learning by rote. Boysen's discoveries mean we may have to re-evaluate how we think about primate intelligence.

Curriculum Links
Activity 1: Animal Training
Activity 2: Investigating Animal Intelligence
Consider This!



adaptation, regulation

collecting data,
drawing conclusions,
experimental methods

brain, primates, sense organs

problem solving

behavior, conceptual thought,
higher order thinking skills,


Training an animal to model a behavior, such as getting a lion to jump up and sit on a pedestal, is an arduous, time-consuming task. Watching such behaviors can be exciting, but few in the audience appreciate the trials involved in getting the animal to perform.

Trainers typically reward any motion made by the animal that takes it closer to the desired behavior. For example, you would never train a lion to jump through a flaming hoop by holding up a hoop and telling the animal to "jump through." You'd have to break the task into separate components. First, you would probably have to train the animal to jump. Next, you might have the animal jump over a low stick. Slowly, you would work up to a hoop, and finally, introduce fire. Rewards would be constant throughout the process.

Find out how hard it is to train an animal with this activity, in which you will try to train a classmate to perform a simple task. You will need a bag of popcorn or candy to use as rewards.

  1. Select one student who will play the part of the trainee, and send him/her out of the room. Ideally, the student who will play the trainee will not know any steps in the procedure ahead of time.

  2. Select another student to be the trainer.

  3. Select a behavior to be taught, such as: sit on a desk, get under a desk, sit on the floor, turn in a circle, hop, etc.

  4. The trainer may not use hand or head motions. The trainer's actions are limited to:
    - changing his/her location by walking
    - saying the word "zorch," which will mean good
    - saying the word "yage," which will mean wrong
    - rewarding the trainee with one piece of popcorn for each positive action
    Do not use any words the trainee will understand. Until taught, animals do not understand words spoken by the trainer. Other species do not understand human nonverbal communication, either.

  5. Invite the student back in from the hall and let the trainer begin.

  6. Allow three minutes for the behavior to be taught.

  7. Try the experiment more than once, each time making up different words to mean "good" and "wrong." Choose a different action to be taught.

  1. How did it feel to be the trainee?

  2. What was the most difficult part of being a trainer?

  3. What would you have done differently?

  4. What are some of the concepts that are key to achieving success as an animal trainer?

  • Share experiences you may have had training dogs or other pets.

  • Compare experiences visiting zoos, circuses or amusement parks where animals perform. Do you think animals should be trained to do tricks? Who benefits, the animal or the trainer?


This activity may generate a fair amount of chaos, but it will demonstrate the need for consistency, patience and positive reinforcement when attempting to train an animal to perform a desired behavior. The goal is to spark discussion about the many difficulties involved in training an animal. It's important to emphasize that the person playing the trainee should pretend to be a totally different species, one that does not understand human speech or gestures at all. Human words and even nonverbal communication are totally meaningless to an animal, until the animal is trained to respond to a particular gesture or spoken word.


One characteristic of chimpanzees and other higher primates is their larger brain size. The farther up a species is on the evolutionary tree, the bigger its brain. Over the eons, primates evolved larger and more complex brains. Sheba, the chimp seen solving math problems in this episode of Frontiers, exhibits a high degree of intelligence. In this activity, you'll have to exercise your math skills. After all, if Sheba can do math, so can you!


Skull Diagram A One indication of animal intelligence is brain size. Primates come in all shapes and sizes, and so do their brains. The smallest primate, a mouse lemur, is only about 60g (2 oz.), so its cranial capacity is rather limited. A little higher on the scale are the New World monkeys, more advanced than lemurs, with bigger brains. But the great apes are even more advanced than the New or Old World monkeys. And one relative of the great apes (humans) has the most advanced brain of all the primates! The average ape's cranial capacity rarely exceeds 600 cu cm, while the average human brain has a capacity of 1,350 cu cm.

 Skull Diagram B In this activity, you'll be modeling how specialists in animal behavior measure cranial capacity of species they are studying. The circle on each skull represents the brain capacity of two primates. Measure the diameter of each circle. Then multiply by 200 to approximate the brain capacities in cubic centimeters.

  1. What brain capacity did you calculate for Skull A?
    ________ cubic centimeters

  2. What brain capacity did you calculate for Skull B?
    ________cubic centimeters

  3. What primate do you think each skull belongs to?
    Skull A: ________________
    Skull B:________________

  1. approximately 600 cu cm

  2. approximately 1,100 cu cm

  3. Skull A: chimp; Skull B: human

  • Pioneer ethologist Dr. Jane Goodall worked with chimpanzees for over 35 years. She has shown that chimps not only make and use tools, but display remarkable similarities to humans in terms of behavior. What do you think defines intelligence? Can a chimp or other higher primate be as intelligent as a human?

  • Dr. Francine Patterson spent almost two decades teaching American Sign Language to Koko, a lowland gorilla. Koko has a sign language vocabulary of over 600 words. Dr. Patterson and many other researchers believe that vocabulary development is one of the best indicators of intelligence. Do you think Koko and Sheba the chimp have a true cognitive understanding of the language they have been taught? Is animal communication the same as human language?


Scientific American Frontiers
Fall 1990 to Spring 2000
Sponsored by GTE Corporation,
now a part of Verizon Communications Inc.