Roots of Behavioral & Cognitive-Behavioral Interventions
Although their roots can be found at the beginning of the 20th century, modern behavioral and cognitive-behavioral therapies arose during the 1950s and early 1960s when the scientific study of behavior emerged as a subject with validity in its own right. Disordered behavior was no longer taken to be purely a symptom or indicator of something else going on in the mind. Of inherent concern was its relation to past and current environmental events thought to be causally related to that behavior. Methods developed in animal laboratories began to be tested—in laboratory, institutional, clinical, and school settings—with people who had chronic mental illness or mental retardation and with predelinquent adolescents. Improvements in patient behavior and functioning were often striking. These changes took place against a backdrop of growing dissatisfaction with the prevailing notion that psychopathology typically arose from unobservable psychic causes that were assessed and treated using techniques that seemed to be based more on art than science. In addition, an accumulating literature of outcome studies revealed that much of the psychotherapy as it had been practiced until the early 1960s engendered very modest and largely unpredictable results. Thus contemporary behavior therapies emerged from three distinct psychological traditions: classical or Pavlovian conditioning, instrumental or operant conditioning, and cognitive-behavioral and rational-emotive therapies.
Classical Conditioning
The first major perspective within learning theory approaches is typically referred to as classical conditioning. This perspective dates to the first decade of the 20th century and is largely attributed to the Russian neurophysiologist Ivan Pavlov. Pavlov was interested in studying the structure of the nervous system, in particular, simple reflex arcs between external events (stimuli) and an organism’s behavior (response). He chose to study salivation in dogs in response to food and developed an apparatus that held the dogs suspended in a harness while a small amount of meat powder was deposited on their tongues. He would vary the amount and timing of the delivery of the meat powder and recorded the subsequent variation in the nature and amount of salivation.
What happened next confounded his simple neurologic experiments but opened the way to revolutionary new insights regarding how organisms learn to adapt their behaviors in response to novel environments. Pavlov found that after a few trials his dogs began to salivate when strapped into the harness, well in advance of any exposure to the meat powder on a particular trial. The dogs began to salivate prior to delivery of the food. Naive dogs placed in the harness for the first time did not salivate; experienced dogs that had been through the procedure earlier began to salivate well in advance of the delivery of the food. In effect, the response came to precede the food stimulus, something that could not be explained in terms of simple reflex arcs.
Pavlov’s genius lay in recognizing the importance of this complication, and he shifted his attention from the study of simple reflex arcs to those conditions necessary to support changes in behavior as a consequence of prior experience, which is, learning. He sounded a bell to signal the start of a trial that was followed by the delivery of meat powder and found that he could reliably train the dogs to salivate to the sound of the bell and not to respond to other aspects of the experimental situation. In effect, he introduced a particularly salient stimulus that carried all the predictive information contained in the situation (ringing the bell predicted subsequent delivery of meat powder, whereas nothing happened until the bell was sounded); and the dogs came to salivate reliably only after the bell was rung. Once the bell was established as a particularly informative stimulus, he could occasionally omit the meat powder on subsequent trials, and the dogs continued to salivate to the sound of the bell.
This simple paradigm contained the key elements of classical conditioning. The meat powder represented what Pavlov came to call the unconditioned stimulus. All dogs with intact nervous systems salivate in response to meat powder being deposited on their tongues, whether they have any experience with that stimulus or not. Salivation represented the unconditioned response. The bell (or earlier, the entire experimental apparatus) represented the conditioned stimulus. Dogs did not naturally salivate to the sound of a bell, but they came to do so if it was paired with the meat powder (the unconditioned stimulus). Salivation to the bell alone represented the conditioned response, a learned response to an originally neutral stimulus that is not found universally among all members of the species.
