If animals can think

October 15, 1995|By Elizabeth J. Sherman

PEOPLE HAVE spent ages pondering whether animals think. On Oct. 27, the public will be able to learn more about our mute cousins when Think Tank opens at the Washington Zoological Park.

When you come to Think Tank, bring your reading glasses and be prepared to spend some time. "Think Tank is a cross between a zoo and a museum exhibit," says Lynn Donick, chief of the National Zoo's Division of Exhibit Interpretation and Think Tank project manager. "The subject is complex, and we've included a lot to read."

As you enter the exhibit, a kaleidoscope of photographs of animals in action will catch your eye while a series of monitors displays quick vignettes -- a spider weaving a web, a human sky-diving, a gosling following its mother. Each of these images poses the question: Are these creatures thinking?

To find out, you might do a series of exercises or flip up the flaps covering in-depth explanations of information given more briefly

in cartoons and blurbs on the reader rails. What do scientists really think about the cognitive abilities of seeing-eye dogs? Lift up the flap and see.

In the next section, you will encounter two large and touchable bronze brains and display cases filled with brain models in wax and real brains in bottles. Confronted with the thinking organs of a whale, an elephant, a human, an orangutan, and squirrel, you may begin to wonder about the question of the brain size to brain capacity.

In the "smart" (or language) room, you can watch the orangutan school or play an interactive game to test how well you use language. Panels around the area show "open the big red bag" in 30 different languages (including orangutan symbols), explain what language is, and trace the history of what we know about it through the work of a dozen language researchers.

The real attractions here are the macaques -- with their constant display of threat yawns, lip-smacking greetings and affectionate grooming.

"Very few museum or zoo exhibits have ever attempted to show something that's unobservable," points out Dr. Benjamin Beck, the zoo's associate director for biological programs. Over the past 10 years, his plan to renovate the Monkey House evolved into the wildly innovative Think Tank. "But we are spending $4 million on an exhibit of something you cannot see, taste, hear or smell. Everything we know about animal thinking has to be inferred from the animals' behavior."

Thirty years ago, the ability of various animals to use tools was viewed as the most easily observable sign of intelligence. At Think Tank, researchers also will look at three other factors: evidence of animal communication and "languages," animal societies and willingness to cooperate for the good of the group.

Brains are expensive

"A big brain is an expensive piece of adaptive equipment," James Shreeve reminds us in his forthcoming book, "The Neanderthal Enigma: Solving the Mystery of Modern Human Origins" (Morrow). "You don't evolve one if you don't use it."

NTC Bigger animals naturally have bigger brains -- just as they have bigger limbs. But while an elephant has a bigger brain than a shrew, this does not automatically mean that elephants are "smarter" than shrews.

Because each species is expert in the things it must do to survive, it is no easy task to compare one to another. If a horse, for instance, is asked to stomp a lever to make a response in a laboratory test, what should a fish be expected to do? And in addition to differences in physical capabilities, differences in sensory ability dictate that rats will do badly when asked to distinguish between two shapes but will rack up a far better score than a human when asked to discriminate among smells.

But motivation can be just as crucial as ability. Some animals are just not interested in playing the laboratory test game, and even the question of rewards is tricky. A horse would do miserably on a test where the reward was a worm, just as a fish would be unwilling to work for a carrot.

It is obviously easier -- and more satisfying -- to compare the thinking capacity of animals within a closely related biological group. Scientists will cautiously allow that primates, for instance, whose brains are relatively large compared to their body weight, tend to do better on standardized problem-solving tests than do closely related species with relatively smaller brains.

But even that statement has to be qualified.

"It may turn out that the intelligence of humans, chimps and gorillas and monkeys is simply not comparable," says Dr. Beck. "Finding equitable ways to explore thinking processes is one area Think Tank will explore."

Thinking is hard to define even if you know it when you see it.

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