Behaviorism is a systematic approach to understanding human and animal behavior through observation and measurement of external behaviors. It emerged in the early 20th century through the work of psychologists like Ivan Pavlov and John Watson who sought to study behavior objectively without relying on introspection. Behaviorism influenced education through concepts like segmented instruction, operant conditioning using reinforcement and feedback, and behavior modification to change behaviors. Behaviorist teaching methods focus on shaping behaviors through reinforcement, repetition of skills, and assessment of observable behaviors.