Page 80 - Understanding Psychology

Figure 3.4 The Visual Cliff
Infants display the ability to perceive three- dimensional space. Infants’ heart rates increased as they approached the perceived dropoff of the visual cliff. Why do you think researchers measured the infants’ heart rates during this experiment?
66 Chapter 3 / Infancy and Childhood
THE DEVELOPMENT OF LANGUAGE
Language and thought are closely intertwined. Both abilities involve using symbols. We are able to think and talk about objects that are not present and about ideas that are not necessarily true. A child begins to think, to represent things to himself, before he is able to speak. The acquisition of lan- guage, however, propels the child into further intel- lectual development (Piaget, 1926). We have been able to learn a good deal about the acquisition of language from animals.
Can Animals Use Language?
Psychologists believe that chimpanzees must develop at least as far as 2-year-old humans because, like 2-year-olds, they will look for a toy or a bit of food that has disappeared. They can represent the existence of that toy or bit of food in their minds. Can they be taught to “talk” about it? Allen and Beatrice Gardner raised a baby chimp named Washoe in their home and, since chimps are very good with their hands, taught her to use the American Sign Language for the deaf. At 31⁄2 years of age, Washoe knew at least 87 signs for words like food, dog, and toothbrush. By age 5, Washoe used more than 160 signs.
Several chimpanzees have been taught to con- verse in other ways. Chimpanzees have been trained on special typewriters connected to computers. One chimpanzee, Panzee, used a special computer key- board with symbols to communicate with humans (see Figure 3.5).
The chimps use only aspects of the human lan- guage. Chimps use words as symbols but do not apply grammatical rules. The ability to arrange symbols in new combinations to produce new meanings is especially well developed in the human brain. The rules for such organization of symbols are called grammar. Grammatical rules are what make the sentence “the rhinoceros roared at the boy” mean the same thing as “the boy was roared at by the rhinoceros.” It may be in our ability to use such grammatical rules that we surpass the simpler language
of the chimpanzee.
How Children Acquire Language
Some psychologists argue that language is reinforced behavior, while others claim it is inborn. Some people claim there is a critical period, or a window of opportunity, for learning a language. For example, songbirds