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Photo of Marc Hauser Marc Hauser as seen on
Animal Einsteins: No Fools About Tools

Click on Marc's photo to read a brief bio.

q I would really like to have a tamarin as a pet. Is this possible, and if so how could I obtain one? Anne and many other viewers.

A Cotton-top tamarins cannot be obtained as pets. they are endangered species. In general, most monkeys do not make for good pets, and I actually think that it is cruel. They are highly social, and enjoy being with other members of their species.

q Why did you use tamarins in the experiments rather than chimps? Is there a special characteristic about tamarins that chimps don't have, or do you think we already performed enough experiments on chimps? Lincy

A Excellent question. I am interested in how the capacity for different kinds of thoughts and representations evolved in different species, how we share some characteristics with other animals, and how we differ. This kind of logic can be applied in another way, one that is often less familiar. We can also look at how, for example, chimpanzees and tamarins are similar and different, and why. For example, chimpanzees live in large social groups that break apart into small groups for short periods of time, and then break apart again; this is called a fission fusion society. In contrast, tamarins live in monogamous societies, typically a breeding pair and their kids. An interesting question, then, is how social organization shapes the mind of a species? Are species with different social organizations always different in terms of how they think and what they think about, or are they similar? So, tamarins provide a window into how a species with a different social organization thinks about the world.

q Looking at the experiment where you change the apple from box to box and the monkey reacts, certain things come to mind: First, the monkey does appear to notice the apple is being changed locations - just look at his head as the apple is moved and secondly in the last sequence where Alan goes for the apple in the wrong box, the monkey might be staring longer because he can't understand why Alan is going to the wrong box (as I said I believe the monkey noticed the apple being moved ). Can you comment on these thoughts please? AJ

A Good question. The important design feature of our experiment is that you have to compare how long the monkey looks in the condition where Alan leaves the room with the condition in which Alan stays in the room. In both conditions, Alan either searches in the box with the apple or the box without the apple. The results show that the tamarins look longer when Alan searches in the box with the apple when he has left the room (that is, he doesn't know about the switch), but look longer when he searches in the empty box when Alan stays in the room (that is, he should know where the apple is because he watched the transfer).

q Can you recommend a book which presents a balanced approach to animal cognition, and which reflects the kind of research insights reported the program? Thanks for any ideas, and for a most interesting research project! Robert Ranger

A Robert, Well, I have just finished a book for Henry Holt called "Wild Minds: What Animals Think" which should be published in the fall of 1999. If you don't want to wait that long, take a look at a now somewhat outdated book, but good nonetheless, by Dorothy C. Heney and Robert Seyfarth called "How Monkeys See the World." It is mostly about primates, but is well done.

q I teach high school physics in Green Bay, WI. I was interested in the tamarins and their views on gravity. I often have students who will also not change their views on a scientific concept even with overwhelming evidence. I would like to explore this idea further. How often am I trying to teach against deeply ingrained thought patterns? What strategies can I use to overcome this? I am interested in extra course work on how students learn. Do you know of anyone I can contact? It may be interesting to devise an experiment that compares my students ingrained views against your tamarins. Gary Baier

A Gary, What a wonderful question. One of my colleagues, Susan Carey (NYU- Psychology department) has written extensively on the fact that children go through periods of conceptual change that approximate Kuhnian scientific revolutions. There is a new book out by Alison Gopnik and Andrew Meltzoff (MIT press) that also goes through these ideas, covering different domains of knowledge such as objects, number, naive physics, naive psychology and so forth. It is an important area of research that unfortunately, in my opinion, had made very little impact on education. It would be fantastic if you could look at this material and begin to integrate it into your teaching. I will also be publishing a book in Fall of 1999 (Henry Holt) called Wild Minds: What animals think, that will similarly take this approach to animals, and compare them with children and infants. Good luck!

q Great show. My kids (ages 3 to 9) were spellbound. Here are our questions:
  1. Are individual animals used in multiple experiments?
  2. If an individual animal participates in experiment "one" and then experiment "two," wouldn't the experience gained in the first experience influence the animal's performance in the second?
  3. If individual animals are used in multiple experiments over time, could they reach a point were they are not representative of the animal family that was the original test subject, but rather represent a new class/family based on their greater interaction with humans and the experience this interaction has provided?
Rich, Katy, Amelia and Molly

A Glad your kids liked the show. Yes, we do use individuals in different experiments.

Your second is an excellent question. There is certainly the potential for experience in one experiment to influence the outcome of another experiment. The critical issues here is the kind of question one is interested in. For some experiments, we are simply interested in an animal's potential to solve a problem, regardless of its training or history. If it solves the problem, or fails to do so, we can then ask why? Did they succeed or fail because of prior history, or in spite of it? Sometimes we systematically look for effects. Thus, for example, in the tubes experiment, individuals tested with vertical first failed, but then passed on horizontal tubes. Interestingly, subjects tested with horizontal first, who passed, then went on to fail the vertical. What this shows is that prior experience has no influence. The vertical tubes are simply harder, and presumably, this is because of the gravity effect.

With regard to your last question, there is no question that animals in captivity have unique experiences. Few of us try to make the claim that this is what an animal in nature would do. In fact, the reason why I work in the wild is precisely because I am interested in what animals do naturally. The work on numbers that you saw with Susan Carey [the Number Crunchers story on this episode] is a joint project. Susan and I work together comparing rhesus monkeys in Puerto Rico with tamarins in captivity with babies in a lab at NYU. When we find similarities, we can confidently claim that the environment has had little effect. But you are absolutely correct in saying that a history of experience influences them. One more point. What distinguishes our work from most of the work presented in the show is that we don't train our animals. Most of the tasks we use in captivity and in the field involve spontaneous exposure to experimental conditions. Thus, we use the looking time task to see what animals expect, and this has the virtue that we have not trained them.

q What is the age group of the tamarin monkeys used in the experiments? How many boxes of Fruit Loops do you go through every week? What was the pink stripe on the monkey's head for? Mrs. Jordan's Fifth Grade Science Class

A All of the tamarins are adults. Tarmarins reach adulthood quite quickly (about 1-2 years of age). We actually don't go through that many Fruit Loops because we give them small pieces. Also, too much sugar is bad for them. Most of their food comes at feeding time when they receive crickets, mealworms, yoghurt, sunflower seeds, peanuts and some special fruit treats.

Ahh yes, the pink hair. Too bad they didn't say something about this on the show. About six months before the airing of the show, we conducted an experiment to see if tamarins would recognize themselves in the mirror after having their hair dyed while they were sleeping. In a previous experiment on chimpanzees, when a red mark was applied above one ear and one eyebrow, the chimps woke up, looked in the mirror and touched the marks. This shows that they recognize their mirror image. Some of our tamarins did the same, but not nearly as many, or as dramatically, as with the chimps.

q Was the element of sound considered in the test of the 3 openings, with a tube attached to one, when the nugget of food was "flicked" down it, and hit the door at the other end, nearest the tamarin? I thought that was why he knew where it was, not just because he remembered the idea of the tube, or understood anything about gravity. Lynn

A Good question. First, in the real test (no TV), we used white noise to mask the sound of the food hitting the door. But more importantly, if you think about the results from the vertical test, they actually fail. That is, if they were using sound to track the object, they should have succeeded. But as you saw, they continuously went to the door without the food.

q The tamarins were presented with hooked sticks or pieces of cloth to retrieve a piece of candy. It seemed to me that, at least on the TV, the correct choice was always on the tamarin's right hand side. Could that have influenced their selection? Hilke

A Throughout the experiments, the side in which a correct choice was present/available was varied. Thus, no side bias was possible.


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