American psychologist B.F. Skinner developed the behaviorist approach, which began with Ivan Pavlov's famous experiment in which he conditioned dogs to salivate at the sound of a bell. Skinner's was a therapeutic strategy of behavior modification based on conditioning. The audio-lingual approach to language learning is based on Skinner's techniques and uses listen/repeat exercises, drills and positive reinforcement from the instructor. Audio tapes or CDs give students the means to practice on their own, and classroom sessions often involve short, repeated exchanges between the instructor and the student.
According to Jean Piaget, proficiency in certain skills, including language skills, depends on a combination of developmental readiness, social interaction and the student's own interpretations. His experiments have been implemented with adults as well as children, and educators have applied many of his theories in the realm of language learning. Hence, many ESL classrooms have discussion groups, pair work interactions and class presentations. Many ESL instructors rely heavily on these peer-to-peer interactions because students are more likely to experiment with each other than they are with the instructor.
Proponents of Cognitive Learning Theories maintain that Behaviorism is too mechanistic an approach, and that learning is a complex affair that unfolds through trial-and-error and experience. Interpreting life experiences and solving problems are activities that facilitate language learning by providing personal insight. To this end, instructors using methodologies based on these theories may provide space in the classroom for real-life discussions about personal matters, or encourage extracurricular student activities that are conducted in English. In the process, the instructor may assume an egalitarian role within the classroom, becoming a cohort or friend rather than an authority figure.
Psychologist James Asher based the method of Total Physical Response on the structural view of language, which maintains that the most basic character of language is its phonetic quality. By listening, much as a baby listens to its mother, a language learner gradually begins to understand grammatical units, grammatical structures and words. Asher believes that listening should develop before speaking, so classroom curricula incorporating his methodologies include a large amount of passive listening. They also include command/response exercises in which a student must respond, either verbally or non-verbally, to an oral instruction.