Human language has a hierarchical structure. A phoneme (or sound) is the smallest unit of speech that can be distinguished and named. The English language consists of 26 letters in the alphabet that contribute to 44 phonemes (e.g., the word bat contains three distinct sounds: /b/, /a/, /t/). A morpheme is the smallest unit of meaning in language. Words, prefixes, and suffixes can be morphemes. In English, adding -s to the end of most nouns indicates there are multiple instances of that noun.Phrases are words grouped together to create a specific meaning, although phrases rely on larger units of grammar to create a complete meaning. Sentences are at the top of the hierarchy. They contain a subject and verb and indicate a complete thought. Syntax refers to the system of rules used by a language specifying how words may be arranged in sentences. Syntax is sometimes used as a synonym for grammar, but syntax is more properly a subset of grammar. Grammar is the way sentence parts (for example, subjects and their modifiers or verbs and their modifiers) are related to one another in a sentence.
Building Blocks of Language
Chomsky's theory of innate, universal grammar and the existence of a "language acquisition device" in the brain were treated as a scientific fact for many years. But recently Chomsky's theories have been challenged, mostly by evolutionary biologists who propose that only the brain's general abilities are innate, or determined by factors present at birth. They argue that there is no grammar program or language acquisition device located in the brain. Instead, they suggest there is a language system that relies on various parts of the brain working together. Interactionist theorists propose that both biology and experience are responsible for language development, suggesting humans are well equipped to learn language.
Brain Regions Involved in Language Processing
Language development appears to be universal. The first stage is babbling, which begins at around six months when children begin repeatedly uttering one-syllable sounds. Deaf children exposed only to sign language babble with gestures. The second stage occurs around age one, when children begin uttering single words. Parents or other adults naturally help children acquire language by speaking to them more slowly than normal and in a higher-pitched voice called "motherese" or "parentese." Adults also use simple sentences and repetition.
Around age two, children begin uttering two-word combinations expressing various actions. Scientists say toddlers already know the basic rules of grammar before they can string sentences together. For example, English-speaking children who want to be picked up are likely to say, "Me up" rather than "Up me." In this stage, children use telegraphic speech, a developmental step in language formation involving the omission of small words such as articles and prepositions from sentences. The last stage of language development occurs around age four, when children begin forming complete sentences of three to eight words. Children vary in how long it takes them to go through the four stages of language development, with variations of up to a year or more.
The acquisition of a second language is easier at younger ages. German biologist Eric Lenneberg (1921–75) hypothesized that the critical time for language acquisition ends with puberty, when brain functions are married to specific portions of the brain, which becomes increasingly inflexible. He also said that the ability to acquire a native accent in a language disappears at around age 10. However, other researchers say the window may extend beyond puberty. A person moving to a new country is likely to learn the language more quickly through acculturation, a process through which they become socially and psychologically integrated in their new environment.
Language Shapes Thought
Thus, the matter of how language shapes thinking is something of a chicken-egg dilemma. Do the cultures and worldviews of the Hopi and European Americans shape their language or vice-versa? Or is this process interactive? More recent research on linguistic relativity supports Whorf's assumptions to some degree. For example, people who speak African languages without separate words for blue and green discriminate those colors differently than English speakers, such as by referring to a different color spectrum. The Himba tribe of Namibia recognizes shades of green that are not classified in English. The Dani of New Guinea recognize only light (warm) and dark (cool) colors by language but can identify various colors (e.g., “red, yellow, white” and “blue, green, black”) within those spectra. Other studies have found that language has some effect on how people think about motion, time, and shapes.
Much thinking requires language, but people do experience imagery and sensation not accompanied by words. Moreover, verbal and visual thinking often occur together. A recent study found that when subjects were prompted to use verbal thinking, they still created visual images to accompany their internal speech. These results indicate visual thinking is deeply ingrained in the brain. Earlier research found that people thought visually about what was close to them (in space or time and also emotionally) but used inner speech to think about what was at a distance.
Animal Cognition and Communication
Many species can form concepts, show numerical awareness, use tools, display insight, and communicate through sounds and gestures. For example, a dog can bark or wag its tail, and a peacock displays its feathers to attract mates. Bees indicate to their hive mates that they have found nectar by dancing, and birds use sounds in intricate systems of communication. Communication is not language, however, and it was long argued that animals did not possess the ability to create or understand the abstract symbols used by language. But some scientists believe that certain forms of animal communication reflect language use. Dolphins communicate with clicks and whistles and can understand human hand signals. American marine biologist Louis Herman concluded that dolphins had language comprehension and the ability to understand syntax.
American animal psychologist Francine Patterson taught a gorilla named Koko 1,000 signs, while psychologists Beatrix and Allen Gardner taught the chimpanzee Washoe 250 signs. Some scientists remain skeptical, however, about whether the signing of primates is real language or merely imitation and the effect of conditioning. Another famous instance of animal communication is the work done by American psychologist Irene Pepperberg with Alex the parrot, who learned to distinguish colors and shapes and to count numbers. He acquired about 150 English words. Pepperberg claims Alex displayed the intelligence of a five-year-old human.
Elephants are another animal species known for their intelligence. Like humans, their cerebral cortex is highly convoluted. This increases the surface area, allowing for more connections between neurons. Some evidence suggests elephants can understand death and perhaps mourn their dead.