Operant Conditioning - Thorndike's Law of Effect

Thorndike's Law of Effect

Operant conditioning, sometimes called instrumental learning, was first extensively studied by Edward L. Thorndike (1874–1949), who observed the behavior of cats trying to escape from home-made puzzle boxes. When first constrained in the boxes, the cats took a long time to escape. With experience, ineffective responses occurred less frequently and successful responses occurred more frequently, enabling the cats to escape in less time over successive trials. In his law of effect, Thorndike theorized that successful responses, those producing satisfying consequences, were "stamped in" by the experience and thus occurred more frequently. Unsuccessful responses, those producing annoying consequences, were stamped out and subsequently occurred less frequently. In short, some consequences strengthened behavior and some consequences weakened behavior. Thorndike produced the first known learning curves through this procedure.

B.F. Skinner (1904–1990) formulated a more detailed analysis of operant conditioning based on reinforcement, punishment, and extinction. Following the ideas of Ernst Mach, Skinner rejected Thorndike's mediating structures required by "satisfaction" and constructed a new conceptualization of behavior without any such references. So, while experimenting with some homemade feeding mechanisms, Skinner invented the operant conditioning chamber which allowed him to measure rate of response as a key dependent variable using a cumulative record of lever presses or key pecks.