ier for a chimp than ASL is. Because the symbols were right in front of her, she could use them as cues to remember the meanings. One disadvantage was that Sarah became mute when she didn't have her symbols.In another research project, Duane Rumbaugh taught a chimp named Lana to use a special typewriter linked to a computer. It had fifty keys, each showing a geometric configuration that represented a word. When Lana typed a configuration, it showed up on the screen in front of her. She learned to correct herself by checking the sequence of configurations as they appeared. Lana learned to respond to humans who "talked" through the computer and she initiated conversations. When Lana came across an object that she hadn't been taught a word for yet, she sometimes made up her own.Some researchers have argued that language-trained chimps use symbols and signs meaningfully and accurately. They are able to refer to things that have been removed, like ball they previously saw but that is now put away in a box. Also, like Lana, there is evidence that chimps can make up new appropriate word combinations using simple grammar rules. This suggests that chimps may have at least some understanding for elementary syntax.Not all researchers agree with the above view. Psychologist Herbert Terrace spent almost four years teaching sign language to a male chimp named Nim. Terrace was convinced that this chimp was really combining words into grammatical groups similar to a child's first sentences. But after analyzing his data, he began to doubt this. For example, a child's sentences rapidly grow in length and complexity as the child learns more grammatical rules; Nim did not show the same progress. Even though he did produce some lengthy sequences, his mastery of syntax did not grow. Terrace analyzed videos showing conversations with Nim which showed that much of his "talk" was partial imitations of things the researcher had just said. This l...
