According to Schloss and Smith (1998) applied behavior analysis has its roots in behavioral theory, which states that most behaviors are learned responses to environmental stimuli. B.F. Skinner (1953) extended behavioral theory by investigating operant conditioning. After his work, Skinner presents three important principles of operant conditioning: reinforcement, extinction, and punishment. Another important author, who contributed with the behavioral theory was Albert Bandura, who in 1965 and 1977; he can explained that individuals learn new behaviors throughout observations of others’ performance.
