Pavlov’s Major Ideas

Ivan Pavlov’s discovery of the principle of classical conditioning or conditioned reflexes  is the reason he is a household name today. A physiologist by training, Pavlov discovered conditioning during his experiments on the digestive systems of dogs, when he observed that gastric juices are produced even if food never reaches the stomach.  In the course of his research, Pavlov noticed that when the lab worker who normally fed the dogs entered the kennel, the dogs would begin to salivate, even if the technician was not bringing food into the room. Pavlov demonstrated that there are two basic types of responses, conditioned and unconditioned. In dogs, an unconditioned, or innate, response is salivating at the smell or sight of  food. A conditioned response occurred when the lab technician who normally fed the dogs entered the room and caused the dogs to salivate. The technician became the stimulus instead of the smell or sight of the food, such that the dogs began to associate his presence with feeding time. Pavlov spent the rest of his life experimenting with these responses, testing them with variables such as the use of a metronome to measure the passage of time, and of course using other audio cues in his famous bell experiments. By pairing an unconditioned stimulus (meat), with a conditioned stimulus (a bell), he discovered that he was able to produce the same salivary response with both stimuli.

Pavlov’s research on the digestive system, although influential at the time, is far eclipsed today by his work on classical conditioning.  He was the first to discover and study behavior modification using stimuli, a principle which gained him international acclaim and secured him a place as one of history's most important scientists.  Although he did grasp the implications of conditioning on humans, it was his successors who extended his ideas into the fields of psychology, education, and politics.