Behaviorism is a psychological approach that states human behavior can be understood without reference to mental states. Key aspects of behaviorism include: conditioning as the process of learning through stimulus-response associations; the study of only observable behaviors; and influential figures like Ivan Pavlov, B.F. Skinner, and Albert Bandura who contributed concepts like classical conditioning, operant conditioning, and observational learning. In the classroom, behaviorism emphasizes shaping student behavior through reinforcement and repetition.