The purpose of this article is to explain how phobias develop and how systematic desensitization can be used to overcome these phobias using the principles of classical conditioning. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay The main principles of classical conditioning are acquisition, extinction, habituation, and counterconditioning. “Classical conditioning helps explain many behavioral phenomena, particularly phobias and addictions.” (Michael S. Gazzaniga, 2018). Classical conditioning is a type of associative learning in which “An organism learns to associate two stimuli in such a way that one stimulus comes to elicit a response that was originally elicited only by the other stimulus” (M. Passer, R. Smith, N . Holt, A. Brenner, E. Sutherland & M. Vliek,2009). A phobia can be defined as an “extreme, irrational fear of a specific object or situation” (The Editors of Encyclopedia Britannica, 2019). Frequent exposure to a phobia is known as systematic desensitization and can help overcome phobias. “Systematic desensitization is a form of gradual exposure.” (Lynne M. Drummond and Isaac Marks, 2015). Through systematic desensitization, a phobia can be counterconditioned whereby an animal/human who has previously been conditioned to react to a certain stimulus is trained to react differently to the same stimulus. This essay will outline how phobias develop, the different processes of classical conditioning (acquisition, extinction, habituation, and counterconditioning), and how the process of systematic desensitization and counterconditioning can help overcome fears and phobias. Classical conditioning was developed by a Russian physiologist named Ivan Pavlov in 1890. Pavlov first developed this theory through his experiments on the digestive system of dogs. Pavlov created a device that collected saliva from dogs and noticed that dogs salivated at the sight of the person feeding them. “One day he noticed with annoyance that laboratory dogs drooled before tasting food” (Michael S. Gazzaniga, 2018). The dogs associated the lab technician with food. This prompted Pavlov to develop a theory of the relationship between stimuli and responses that he believed could be applied to both humans and animals. This theory is now known as classical/Pavlovian conditioning. “Learning is a relatively permanent change in an organism's behavior as a result of experience” (Bryan Kolb and Ian Q. Whishaw, 2014). According to Michael S. Gazzaniga “We predictively learn associations through conditioning, the process that links environmental stimuli to behavior” (2018 page 210). The first period of classical conditioning is known as the acquisition period. According to M. Passer, R. Smith, N. Holt, A. Brenner, E. Sutherland, and M. Vliek “Acquisition refers to the period during which a response is learned” (2009, p. 284). first introduced the unconditioned (unlearned) stimulus. “In fear conditioning, a noxious stimulus is used to elicit fear, an emotional response. According to Bryan Kolb and Ian Q. Whishaw, "A challenge for psychologists studying memory in laboratory animals (or people) is getting subjects to reveal what they think. They can remember. Since laboratory animals do not speak, researchers must devise ways in which a subject can display their knowledge” (2014 page 483).be passed through the grill floor. A tone sounds just before a brief, unexpected, mild electric shock. (2014, p. 484). The tone is the unconditioned stimulus as it is “A stimulus that elicits a response, like a reflex, without prior learning” (Michael S. Gazzaniga, 2018). Here, in the acquisition period, the rat learns an unconditioned and fearful response. “An answer that does not have to be learned, like a reflex” (Michael S. Gazzaniga, 2018). The rat may freeze and remain still or “become immobile and urinate in anticipation of shock” (Bryan Kolb and Ian Q. dWhishaw, 2014). The tone must be emitted multiple times to create a noticeable response from the rat, making the tone a conditioned stimulus. “A stimulus that elicits a response only after learning has occurred” (Michael S. Gazzaniga, 2018). This repeated sound of the tone is known as systematic desensitization. Systematic desensitization occurs during acquisition in which “A conditioned stimulus (e.g., a tone) typically must be paired multiple times with an unconditioned stimulus to establish a strongly conditioned response” (M. Passer, R. Smith, N. Holt , A. Brenner, E. Sutherland and M. Vliek,2009). “When the tone is subsequently presented without shock, the animal behaves in a fearful manner.” (Bryan Kolb and Ian Q. Whishaw, 2014.) The fear observed in the rat is evidence of associative learning “linking two stimuli, or events, that occur together” (Michael S. Gazzaniga, 2018). Fear is a conditioned response “A response to a conditioned stimulus; a response that has been learned” (Michael S. Gazzaniga, 2018), and tone is now a conditioned stimulus is “A stimulus that elicits a response only after learning has taken place” (Michael S. Gazzaniga, 2018) . In this case the rat has developed a tone phobia. During this process, if the rat in the same environment was presented with a different unconditioned stimulus, for example a light, this would have little effect on the animal as the rat has now developed a phobia of sound. association between tone and shock and a tone phobia. This addition of an alternative external stimulus is known as counterconditioning. Extinction of a phobia can be achieved through processes of systematic desensitization and counterconditioning. “Counterconditioning was the inspiration for systematic desensitization, a behavioral therapy technique in which frightening conditioned stimuli are deliberately paired with relaxation during therapy” (Wolpe 1958). Here light is an external stimulus that triggers the extinction process. “Extinction is a process in which the conditioned response occurs repeatedly in the absence of the unconditioned stimulus, causing the weakening and finally disappearance of the conditioned stimulus” (M. Passer, R. Smith, N. Holt, A. Brenner, E. Sutherland and M. Vliek, 2009). Pavlov studied "extinction" and found that the conditioned response decreases if the conditioned stimulus is repeatedly presented without the unconditioned stimulus after conditioning. The period of decreased behavioral response is known as habituation. According to Michael S. Gazzaniga “Habituation is a decrease in behavioral response after repeated exposure to a stimulus” (2018, page 209). In the case of the rat confined in the box, the tone may be emitted several times, this time without the subsequent shock. In the rat the same fear response as before can be observed. The rat can remain still waiting for the previous shock of electric current. Whenever the conditioned stimulus (the tone) occurs without the shock, the conditioned response (the fear) begins to diminish. “The level of fear has been reduced to 50% of its maximum value or, ideally, has vanished.” (William C..