Behaviorism is a school of thought in philosophy and psychology that focused on only studying concepts that were observable like behavior and ignoring those that were invisible to the eye such as the mind (1). The term was coined by John Watson.
Behaviorism before John B. Watson
People usually think that Watson was the one who invented the innovative ideas that pertained to behaviorism, but the truth was that they were appearing in different countries throughout time. The concept that outside experiences and not mental processes were what shaped individuals was central in British empiricism (2); it was also an important point of view in the discussion of nature vs nurture. Moreover, physiologists spread in the 19th century ideologies known as materialistic and mechanistic. The former is the idea that everything is either physical or can be reduced to a physical component (3). The latter is similar, it is the point of view that natural processes can be reduced to matter and motion (4). In addition, August Comte, a French philosopher, developed positivism, which is the notion that knowledge should only come from observable experience (5). A picture of John B. Watson can be found to the right. These ideas started to infiltrate psychology. For example, in experimental psychology, psychologists decreased the use of studies that required introspection and instead were interested in experiments that used animals such as maze studies. Additionally, there were statements like those of James McKeen Cattell that asserted that their laboratory focused very little on introspection, and that behavior, and not the study of mental processes, contributed more to the general pool of knowledge in psychology (6).
Many of you might have heard of Ivan Pavlov. He won the Nobel Prize for his research in digestion. Pavlov conditioned dogs to salivate when they heard the sound of a bell. He was the director of the Institute of Experimental Medicine and trained his new students, which usually were physicians that were trying to get their PhD, to replicate old studies about digestion.
He designed several types of experiments. One of them was collecting stomach fluids by using a technique that is now known as the "Pavlov's Pouch." This is a cut made in the stomach that collects fluids without being contaminated by the food (7). The fluids were sold to other labs so they could study them too, as well as to the public because it was marketed as an elixir that helped with digestion. However, his most notorious experiment involves the recollection of saliva. Before we go into detail about Pavlov's conditioning experiment, it is important to describe one conducted by S. G. Vul'fson who was one of Pavlov's students. This experiment explored the amount of saliva produced by dogs when shown dry or moist food. After initial trials, the dogs started to salivate when they expected the food. This messed up the data, but interested Pavlov because the salivation was consistent. Thus, the Institute created a research laboratory known as the Tower of Silence. The name came to be because there were rooms that were soundproof so that the dogs would not be influenced by sound.
There were four terms that were central to his theory. To explain each concept the concept Unconditional stimulus (UCS), which is a stimuli that can cause a response, but does cause a learned reflex (In this case, the UCS is the food. The unconditioned reflex (UCR), is an unlearned response. In this case, the UCR is the salivation by the dog. The third term is conditioned stimulus (CS). This refers to a stimulus that would not have caused a response if it had not been conditioned. In this case, the CS is the bell. Finally, the conditioned reflex (CR), is the learned response to the CS. In this case, it would be salivation. In other words, a bell doesn't cause a dog to salivate (UCR), but food (UCS) does. However, when a bell and food are paired, the dogs starts to salivate (CR) when it hears the bell (CS) because it expects food.
6. "A History of Modern Psychology," by C. James Goodwin