Skinner developed a behaviorist theory of learning based on the idea that human behavior is shaped by reinforcement and consequences rather than internal mental processes. He identified three types of reinforcement that can shape behavior: positive reinforcement through rewarding desired behaviors, negative reinforcement by removing undesired stimuli for behaviors, and punishment to decrease undesired behaviors. Skinner's theories emphasized using reinforcement principles to arrange effective teaching contingencies and program instruction to efficiently bring about learning. His ideas influenced the development of drill-and-practice and tutorial educational software.