After further study, scientists realized that, although chimpanzees are so like us in many ways, both biologically and behaviorally, there are differences in the vocal tracts of chimpanzees and humans. If we survey the whole range of the communication signals of chimpanzees on one hand and humans on the other, however, we find striking similarities. When two chimpanzees greet each other after a separation, their behavior often looks like two humans in the same situation. Chimps bow or crouch to the ground, hold hands, kiss, embrace, touch, or pat each other on the head, face, or other parts of the bodies. A male may chuck a female or an infant under the chin.
Chimps also have a wide range of calls that convey all different types of information.
A chimpanzee in danger screams so other chimps will be aware of his situation. In short, chimps can and do share basic information about situations and individuals through sophisticated calls and gestures. But humans can communicate abstract ideas, benefit from the experiences of others, and make intelligent, cooperative plans about the future, which chimps cannot do. We know that it is not because chimpanzees do not have the intelligence or because their lives are so simple they do not need communication. But human s lives have become much more complex.