Cognition or Association?

In his book Learning and Memory: An Integrative Approach, David A. Lieberman discusses the issue of language in chimpanzees in terms of cognition and associations. Further, he makes note of some prominent cases surrounding this issue. Initially, scientists had attempted to teach chimpanzees to speak but after failed attempts it was decided that it was physically impossible. In an attempt to surpass these limitations, Allen and Beatrice Gardner taught American Sign Language to a chimpanzee named Washoe with great success. In another similar effort, Duane Rumbaugh and Sue-Savage Rumbaugh taught chimpanzees “a new language using geometrical shapes that they called lexigrams as words. The lexigrams were displayed on a keyboard linked to a computer, and subjects could choose words by pressing the appropriate symbol on the board.”

Despite compelling evidence that suggested that chimpanzees possessed the capacity for human language there was controversy over the nature of this “language.” As Lieberman puts it best:

“If Lana [the chimpanzee] is hungry and touches the lexigram for banana, does this means that she understands what this sign means, or is she simply repeating a movement that was reinforced in the past? A chimpanzee touching a lexigram might be behaving no more intelligently than a rat pressing a bar- both might simply be repeating behavior that was previously reinforced.”

In other words, Lieberman suggests that just because chimpanzees can sign “banana” does not mean that they possess semanticity, the ability to “understand the meaning of the words they are using.” Perhaps the chimpanzees are merely forming associations in which they have learned that the word “banana” will lead to food or a reward.

Still, Lieberman offers a particular piece of evidence in favor of language in chimpanzees that struck me as compelling. When Washoe became a mother her baby was sick and eventually died. As Lieberman mentions, “when Washoe saw her trainer the next day, her first sign was ‘Baby?’ The trainer replied by signing ‘Baby gone, baby finished.’” Lieberman goes on to describe Washoe’s reaction as “dramatic,” “vacant,” and “distant.” To me, this can only suggest that the language exhibited in chimpanzees is part of a complex, cognitive process in which words have meaning. However, as Lieberman mentions “we cannot observe animals’ mental states, and so there will probably always be some level of doubt about the linguistic capacity of chimpanzees.” So unfortunately, until we have the right technology, we probably will not be certain whether chimpanzees merely make associations or possess cognitive abilities. On a sad final note, on October 31, 2007, CNN.com reported that Washoe died of natural causes. For more information about this recent incident go to http://www.cnn.com/ 2007/ TECH/ science/ 10/31/ signing.chimp.dies.ap/ index.html?iref=newssearch .