【新編大學英語】（第一冊）Unit 5 A 動物的文化（3/4）

We have ruled out tool use and invention as ways of telling animal behavior from human behavior. We have also ruled out the learning and sharing of behavior. Yet we still have held onto the last feature – language. But even the use of language can no longer separate human culture from animal culture. Attempts to teach apes to speak have failed. However, this is because apes do not have the proper vocal organs. But teaching them language has been very successful if we are willing to accept other forms than just the spoken word. Two psychologists trained a chimpanzee named Washoe to use Standard American Sign Language. This is the same language used by deaf people. In this language, talk is made through gestures, and not by spelling out words with individual letters.