What Is My Pet Thinking?
Animal Intelligence
Stephen L. Zawistowski, Ph.D.
Cogito ergo sum. (I think, therefore I am.)
—Descartes
Descartes’ simple statement has provided generations of college students with the one thing they remember from philosophy and the only phrase they may know in Latin. But Descartes also built an impenetrable wall between humans and all other living beings. To Descartes, in the early 1600s, thought was a uniquely human attribute, while animals responded to their world in a simple, mechanical fashion. His premise would face many challenges over the ensuing centuries. Today the impenetrable wall is no more than a lace curtain.
In 1859, Charles Darwin published On the Origin of Species, which presented and supported his concept of organic evolution and the continuity among the many species of living things. Implicit in Darwin’s argument was the message that the continuity between species applied to mental as well as anatomical structure and function. This was made clear in his subsequent book, The Expression of the Emotions in Man and Animals, published in 1872. George Romanes, a protégé of Darwin, extended these ideas in his 1882 book, Animal Intelligence. At the time, the field of comparative anatomy had already established methods and protocols for the description and comparison of physical characteristics. Unfortunately, much of the data reported by Romanes was anecdotal, and was not highly valued.
The Horse’s Hoof
Clever Hans was perhaps the most famous horse of his time. Hans’ owner, Wilhelm von Osten, had trained the horse to count by tapping his hoof on the ground. Hans was able to solve a wide variety of math problems, and during demonstrations, was even able to count off the number of men wearing hats in an audience. Hans was quite the sensation in his native Germany, and throughout Europe and America, where he traveled. From all appearances, Hans was a clear demonstration of animal intelligence.
In 1904, the German government established a commission to evaluate this phenomenon. The commission reported that there was no evidence of trickery or intentional efforts to deceive by von Osten. Then Oskar Pfungst, an experimental psychologist, conducted additional observations. In a series of carefully designed and executed experiments, Pfungst showed that Hans was responding to unintentional cues given by his questioners. The horse would begin tapping at the end of a question, probably picking up cues from voice inflections and head movements, and continue tapping until he noticed from some other type of cue that he had tapped the “correct” number of times. If a questioner did not know the answer to the question, Hans would simply continue to tap his hoof.
The report on Clever Hans caused many people to rethink the concept of animal intelligence and its place within an expanding field of experimental psychology. John B. Watson was among those who were leading psychology to more objective, methodology-based behavioral observations. The science of behaviorism, which Watson developed and espoused, became the dominant influence on American psychology for more than half a century. In the 1940s, B.F. Skinner picked up the yoke and took behaviorism to an even more radical formulation. Science had come full circle, and then some. Descartes’ wall between human and nonhuman animals was gone, but so was consciousness. Animals were not the only “machines” responding mechanically to their environments; behaviorism postulated that human behavior was also “determined” solely by reactions to specified conditions.
In the 1970s, consciousness began to reappear in human psychology. Cognitive psychology began to use careful experimental methods to elucidate the internal workings of the mind. Progress in the study of animal behavior resulted in the publication of Donald Griffin’s Animal Thinking in 1984. The field of cognitive ethology has since been developed to study and explain the role that consciousness and intelligence play in the lives of animals. If he reappeared today, Clever Hans might not be admired so much for his ability to count as for his ability to perceive, evaluate and interpret subtle examples of human behavior!
Descartes’ assertion helped to justify centuries of animal mistreatment. The growing body of evidence demonstrating his error should provide the scientific foundations for continued advances in the cause of animal welfare.
Dr. “Z” is senior vice president of ASPCA Animal Sciences and Animal Watch science advisor.
© 2001 ASPCA
ASPCA Animal Watch - Winter 2001
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