Man is a talking animal. Communication via speech is uniquely human. This separates us clearly from the animal kingdom ... In addition to the necessary “software” for speech, we have also been provided with the required “hardware”. Among all other creatures of the earth there is no other that uses articulate speech for communication. It is true that some animals use sounds to communicate, but their cries can hardly be called articulate. And while certain birds can produce an uncanny imitation of human speech, they communicate nothing by their parroting. In fact, there is no animal that is capable of speaking in the manner in which people can speak. Speech is a peculiarly human trait.
In this characteristically and uniquely human activity, man has developed an intricate apparatus made of bits and pieces of anatomy whose primary functions are quite different from those they perform in speech. For the present we need only recognize that from diaphragm to the lips, the various organs that take part in producing talk all have other work to do that is biologically more fundamental. So obvious are the primary functions of lips, teeth and tongue, nose, throat and lungs.
Evolution cannot go to the hardware store and pick the parts it needs to produce organs it has in mind because evolution doesn’t know what it has in mind. It just seems to keep tinkering with what is there until something happens. In the case of the speech machinery, it tinkered with a miscellaneous group of organs dedicated largely to the basic tasks of eating and breathing. Out of them and the very breath of life itself it made speech.
This complexly modulated stream of sound is not mere random or instinctive behavior. It is under the direction of the most remarkable of all Nature’s patchworks, the brain. All but a minute of fraction of speech – the cry or groan of pain, the grunt of extreme physical exertion – is purposive. It is produced to evoke a response, to assist man in his lifelong task of controlling his environment. In order to do this, it somehow gets formed into patterns, which are themselves purely arbitrary, but which are associated in the brain with notions about world around us and how it works.
The circuits of the brain which will ultimately store a vocabulary of thousands of words, along with a complicated set of patterns of arranging them, are at birth completely nonexistent. While voice and the capacity to articulate are inborn, speech must be learned.
Most of us have watched a baby develop from crying to babbling, and from babbling to the momentous utterance of its “first word” (w/c sounds like “mama” to Mama and “dada” to Daddy). But because of this process is going on at the same time that the baby is learning other things – to stand up, to grasp and hold, to fit together, and so on – we may not realize that it is really a different kind of learning. A baby kept by amiable apes would eventually learn to stand, to grasp and to hold, but it would never learn to speak unless, someone would teach them. If this period (critical period hypothesis) is skipped over, the individual will never achieve a full command of language—especially grammatical systems.
Here, then, is a paradox. Speech, the universal human activity, the very mark and defining criterion of humanity and its unique possession, is not an innate part of man’s nature at all. Each individual must experience in himself the task of learning it from other humans. By learning to speak we have certified our humanity and claimed our place in society. But no matter what else we study and learn, all our life long we are aware of our dependence on speech to done the things we feel must be done.