Story of Psychology - Morton Hunt [178]
Here is how Skinner shaped the behavior of a pigeon to peck at a small colored plastic disk set flush in one wall of the Skinner box:
We first give the bird food when it turns slightly in the direction of the spot [i.e., the disk] from any part of the cage. This increases the frequency of such behavior. We then withhold reinforcement until a slight movement is made toward the spot. This again alters the general distribution of behavior without producing a new unit. We continue by reinforcing positions successively closer to the spot, then by reinforcing only when the head is moved slightly forward, and finally only when the beak actually makes contact with the spot.
In this way we can build complicated operants which would never appear in the repertoire of the organism otherwise. By reinforcing a series of successive approximations, we bring a rare response to a very high probability in a short time… The total act of turning toward the spot from any point in the box, walking toward it, raising the head, and striking the spot may seem to be a functionally coherent unit of behavior, but it is constructed by a continual process of differential reinforcement from undifferentiated behavior.58
(Other experimenters, using Skinner’s technique, have constructed far more peculiar behaviors. One taught a rabbit to pick up a coin in its mouth and drop it into a piggy bank; another taught a pig named Priscilla to turn on a TV set, pick up dirty clothes and put them in a hamper, and run a vacuum cleaner over the floor.59)
Skinner likened the operant training of his pigeons to a child’s learning to talk, sing, dance, play games, and in time acquire the entire repertoire of adult behavior. All, in his view, is due to the assembling of long chains of behavior out of tiny links of simple behaviors by operant conditioning. One might call it an Erector-set view of the human being (Homo erectorus?)—a mindless robot assembled by operant conditioning from a multitude of meaningless bits.
Skinner was more or less ignored by the psychological establishment for a long while but slowly acquired a number of devotees—enough, finally, to result in the publication of four journals of Skinner behaviorist research and theory and the creation of a special section of Skinner-type studies within the American Psychological Association (Division 25, Experimental Analysis of Behavior, since renamed Behavior Analysis). Skinner boxes and the techniques of operant conditioning have long been widely used by experimental psychologists. In recent years Skinner’s name and work have been cited in hundreds of behavioral science publications each year (though far less often than Freud’s).60
Still, it was outside of mainstream psychology that Skinner had his major impact.
During a visit to his daughter’s fourth-grade class in 1953, it occurred to him that operant techniques similar to those by which he had taught pigeons to play the piano would make for more efficient teaching than traditional methods. Complicated subjects could be broken down into simple steps in a logical sequence; the students would be presented with questions, and immediately told whether their answers were correct. Two principles would be at work here: the knowledge that one has answered correctly is a powerful reinforcer (reward) of behavior; and immediate reinforcement works better than delayed reinforcement. The result is known as “programmed instruction.”
But since one teacher cannot simultaneously provide reinforcement to a roomful of children, new textbooks would have to be written in which questions and answers were presented one by one, each taking a short step toward