BF Skinner

BF Skinner (1904-1990) was highly influenced by the work of Pavlov and Watson. Concurring with Watson's behavioristic conclusions about the nature of learning, Skinner would attempt to expand upon and more fully explain the phenomena of conditioning. Where Watson limited himself to the pairing of stimulus and response, or conditioning of reflex arcs, Skinner found that learning could occur, at least in humans, in a more complex manor. Skinner recognized that conditioning could occur separate of the stimulus-response loop, in what her termed as operant conditioning.

Operant conditioning, in essence, works in the opposite direction of classical conditioning; where, in classical conditioning both the conditioned and unconditioned stimulus precedes the response, in operant conditioning stimulus is secondary to action. ie. the desired action must occur prior to the stimulus situation. Operant conditioning relies on the motivation of an organism to perform or not perform a particular action, and attempts to control this motivation through the application of either reenforcement, which increases the likely hood of a behavior, or punishment, which decreases the likelyhood of a behavior. Which can in both cases be either positive, the addition of a a stimulus or situation, or negative, the removal of a situation. As such there are four possible types of reenforcement or punishment:

1. Positive Reenforcement - Is the the addition of a pleasant stimulus in response to a desired behavior. It serves to increase the probability of a desired behavior recurring.
2. Negative Reenforcement - Is the removal of an already present unpleasant stimulus in response to a desired behavior. It serves to increase the probability of a desired behavior recurring.
3. Positive Punishment - Is the addition of unpleasant stimulus in response to an undesired behavior. It serves to decrease the probability of an undesired behavior recurring.
4. Negative Punishment - Is the removal of an already present pleasant behavior in response to an undesired behavior. It serves to decrease the probability of an undesired behavior recurring.

Skinner found that by employing this brand of conditioning he was able to condition any simple behavior he desired, and though a process he called shaping he found he was able to condition even the most complex behaviors. Skinner experimented mainly on pidgins, and was able to condition pidgins to perform any number of feats, such as turning in circles or tapping specific sequences or combinations of colored squares. In order to conduct such experiments, Skinner invented a device which he called the Operant Conditioning Chamber (colloquially called the Skinner Box). This was an enclosed chamber with a variety of different apparatus through which to deliver stimulus, along with a food dispenser, to positive administer reenforcement, and an electric grid covering the floor, at administer positive (or in some cases negative) punishment. Skinner also identified that different schedules of reenforcement and punishment resulted in differing success rates. It has often been highlighted that devices such as video-games and slot-machines utilize similar schedules of reenforcement and behavior to illicit repetitive behavior.

While Skinner believed that the combination of classical and operant conditioning could explain all behavior, his contemporary Albert Bandura, identified a third way in which learning occurs. What he identified as observational learning, the basic idea of which is that in many situations learning occurs vicariously through the observation of the behaviors of others. Bandura's bobo doll experiment is widely cited as an example of vicarious learning. In this study children observed a video of an adult playing with a "bobo" doll (an inflatable clown doll). One group of children were shown a video of the adult playing violently with the doll, while the other were shown a video of the adult having minimal interaction with the doll. The children which were shown the violent video were much more likely to play in a violent manor toward the bobo doll than were the children shown the non-violent video.

According to behaviorist theory, the combination of classical conditioning, operant conditioning, and observational learning can account for all learning.