Mindful of Thought
by Alex Hawes
Throughout the course of history, humans have held themselves up on a cognitive pedestal over the animal kingdom. Birds may be able to fly, elephants may be able to uproot large trees, but we humans, at least, can think. In recent years, though, scientists have provided insight into animal minds by studying how their behavior can indicate complex thought. The questions of if and how animals think provoke heated psychological, biological, and philosophical debate. A new exhibit at the National Zoo, called Think Tank, tackles the issue of animal cognition to a degree not seen before in any zoo or museum.
In many ways, Think Tank is a unique endeavor for a zoo. Not simply a display of an animal species, this exhibit "will allow visitors to explore the concept of thinking and, in the process, gain an understanding of the way scientists investigate thinking in animals," according to National Zoo Director Michael Robinson. The Zoo has remodeled the 90-year-old former Monkey House to create not only enclosures for two species of primates--orang utans and Sulawesi macaques--but a setting where zoogoers can witness scientific investigation. The exhibit challenges those who enter to "think hard about thinking."
As the visitor passes through the entrance, he or she encounters a dozen video screens, which show images of various animals exhibiting behavior typical of their species--a beaver building a dam, a spider constructing a web, and so on. Each screen then asks the visitor questions such as "Is this animal thinking?" and "How would you know?" As the visitor continues, an interactive exhibit area offers more specific evidence of animals' complex behavior, and poses more questions about these examples' significance.
Zoogoers journey into the center of the animal brain, literally. A display outlines the anatomy of the brain and the role of its component parts. The exhibit asks people to compare the sizes of different species' brains. You may be surprised to learn that if a squirrel weighed as much as an average human, its brain would be about 50 percent larger than that of a person. However, the display explains, not only the size of the whole brain, but the size of certain individual parts, matters in cognitive processes.
Think Tank graphic displays emphasize three factors crucial to establishing the existence of thought: image, intention, and flexibility. The exhibit provides an example to illustrate what these ideas mean: A visitor comes to the Zoo and, upon arrival, it begins to rain. Opening an umbrella, he or she finds that it's broken, and then decides to buy a poncho. "Image" is defined as a mental representation of something not present--in this case, the thought of shelter, or the idea of buying a poncho. "Intention" pertains to an individual having a goal in mind--wanting to buy a poncho to stay dry, for example. "Flexibility" relates to being able to create a "Plan B" (buying a poncho) if "Plan A" (using one's umbrella) doesn't work. Evidence of each of these three points must be met, according to Think Tank researchers, for thought to be demonstrated.
Using this theoretical framework, the displays focus upon three specific areas in which scientists have traditionally explored human and animal thinking: tool use, language, and social interaction. Tool use was once thought to be unique to humans. However, some animals have shown the ability to manipulate objects to attain certain goals. Chimpanzees use sticks, vines, and bark to "fish" termites out of holes, and they use (and even carry around) particular rocks for cracking nuts. In Think Tank, zoogoers encounter a display of a hermit crab group. Hermit crabs must find new shells periodically as they grow, and select ones that serve to protect them best. Are hermit crab shells "tools?" Would you consider hermit crabs to be thinking when selecting new shells?
Exhibits also challenge people to consider the importance of language communication as an indicator of cognition. Researchers working in Think Tank inform visitors regularly on the progress of the Orang utan Language Project (discussed in the main article), and, in the future, visitors may be able to communicate with the orangs through this language system. Many people might not associate the third and final subject, society, with thinking. Social intelligence, however, can be expressed through alliance-building, cooperation, deception, and other ways individuals manipulate fellow group members for their own benefit. A troop of Sulawesi macaques, housed in Think Tank, provides onlookers with examples of such social complexity.
Sulawesi macaques (Macaca nigra) are mid-sized monkeys found in the wild only on the Indonesian island of Sulawesi. Jessica Hadley is studying the transmission of culture in the Zoo's macaque troop. Visitors can join Hadley in watching how new items introduced to the macaques are used by certain individuals, and how others may imitate fellow group members' novel behavior. Zoogoers can also observe the social hierarchy of these primates, and test their ability to decipher the macaques' dominance relationships. A display of field journals from Zoo primatologist Wolfgang Dittus' 26 years of research on the social behavior of toque macaques (Macaca sinica) in Sri Lanka complement the research going on in the Sulawesi macaque habitat.
Social behavior is also explored in an exhibit of leaf-cutter ants. Leaf-cutter ants in the wild live in colonies of up to several million members, in a complex social hierarchy. Able to defoliate a tree in a few hours, a leaf-cutter ant colony uses harvested leaves in their underground lairs to "farm" fungus, upon which they subsist. A leaf-cutter colony on display at Think Tank will startle zoogoers with the insects' complex behavior and communal efforts. But does this behavior demonstrate thinking?
The Think Tank founders hope to spark interest in the study of animal behavior by allowing zoogoers an opportunity to participate actively in studies normally done only by scientists. Studies of animal cognition, both outlined in exhibit displays and accessible to the general public first-hand through the orang utan and macaque projects, hopefully will cause visitors to come away from Think Tank with a new-found appreciation of animal intelligence. The exhibit stresses the complexities underlying our natural world, and seeks to educate the public about these issues--achieving two of Zoo Director Michael Robinson's goals in developing the National Zoo into a "BioPark."
Benjamin Beck, the Think Tank's project leader, adds, "There is a great deal of understanding of animals to be gained from a visit to Think Tank, but I would consider the exhibit a success if visitors leave only with a better understanding of the way scientists do their work." Researchers involved with this new exhibit also hope that Think Tank will cause zoogoers not only to respect animals' cognitive abilities, but realize the worth in pursuing further study of them, and the need to save them from extinction.
(ZooGoer 24(6) 1995. Copyright 1995 Alex Hawes. All rights reserved.)
First Words (evolution of human speech)
Chipping Away (tool use)
