Maintenance of phobias - Classical conditioning
Learning theories can also help to show why a phobia would be maintained once learned.
Classical conditioning shows how a phobia might be learned. However, classical conditioning tends not to last long so the association would have to be paired often (such as a dog keeps biting), but that tends not to happen.
Watson and Rayner (1920) confirm that classical conditioning does not last long. So classical conditioning is probably not responsible for the maintenance of a phobia normally. Of course if the individual kept getting a dog bite, the fear can be maintained and this would be explained using classical conditioning principles. This can happen, for example, if a panic attack or something similar was experienced while shopping, then the thought of shopping could lead to further anxiety (possibly as strong as a panic attack). This renewal of the association between shopping and anxiety would maintain the phobia.
A fear is normal in the sense that we need to fear things that threaten us, such as being afraid of being high up as we might fall. Phobias tend to focus on something we are afraid of but where the fear is irrational. Nevertheless, a phobia does represent an association between a stimulus (something that makes us afraid) and a response (the fear).
Classical conditioning explains how we associate a response to a stimulus. Also, with a phobia we tend to generalise one extreme fear situation (perhaps being stuck in a lift) to all similar situations (all lifts). Classical conditioning neatly explains such processes and how phobias are acquired.
One-trial learning - This is where the association can be so strong (one trial is enough) that the learning is very hard to undo. This can happen, for example, if you eat bad food, and associate feeling ill with the chicken.