Psychology is the science of behavior. Psychology is not the science of the mind. Behavior can be described and explained without making reference to mental events or to internal psychological processes. The sources of behavior are external (in the environment), not internal (in the mind). Behaviorism is a doctrine, or a set of doctrines, about human and nonhuman animal behavior. An important component of many psychological theories in the late nineteenth century were introspection, the study of the mind by analysis of one's own thought processes. It was in reaction to this trend that behaviorism arose, claiming that the causes of behavior need not be sought in the depths of the mind but could be observed in the immediate environment, in stimuli that elicited, reinforced, and punished certain responses. The explanation, in other words, lay in learning, the process whereby behavior changes in response to the environment. It wasn't until the twentieth century that the scientist !
             began to uncover the actual mechanism of learning, thereby laying the theoretical foundation for behaviorism. The contributions of four particular scientists are Ivan Pavlov, John B. Watson, Edward Lee Thorndike, and B.F. Skinner.
             A Russian neurophysiologist, named Ivan Pavlov (1849-1936), found that if he consistently sounded a tone at the same time that he gave a dog food, the dog would eventually salivate to the sound of the tone alert. Through this research he discovered a basic mechanism of learning called the Conditioned Reflex. A Conditioned Reflex is if a neutral stimulus (i.e. the tone) is paired with a nonneutral stimulus (i.e. the food), the organism will eventually respond to the neutral stimulus as it does to the nonneutral stimulus. Perhaps the strongest application of classical conditioning involves emotion. Common experience and careful research both confirm that human emotion conditions very rapidly and easily. Particularly when the emo...