How does behavioural psychology use classical conditioning to attempt to explain the development of phobias?

Behavioural Psychologists such as Skinner and Pavlov view all aspects of human experience as the result of complex conditioning. They explain phobias as a result of classical. Classical conditioning occurs when a neutral stimulus is paired with an unconditioned response on a number of occasions. A famous example here is Little Albert. A small child with no fear of rats was exposed to a loud bang every time a white rat was placed in front of him. He found the loud bang to be distressing. Eventually, seeing the white rat would induce distress, even without the loud bang. In this example, the unconditioned stimulus is a loud bang. This causes the unconditioned response of fear. The neutral stimulus is the white rat. After a number of repetitions, the rat becomes a conditioned stimulus. Now it invokes the conditioned response of fear. This behavioural explanation is testable using scientific methods and so has good internal validity. On the other hand, behavioural approaches are often criticised for being reductionist, not taking into account other factors such as genetic predisposition to phobias. Similarly, many people cannot trace their phobias back to traumatic experiences.