Systematic desensitisation is one of the main behavioural treatments for phobias. It is based on classical conditioning, with a focus on counterconditioning the specific phobia, i.e. unlearn the maladaptive behaviour. The patient and behaviourist will form an anxiety hierarchy together, in which exposure to the phobic stimulus is gradually introduced. For example, the lowest level for spider phobia would be viewing images of spiders, moving up to the highest level which may be holding a spider. Systematic desensitisation is considered successful when the highest level is achieved without anxiety, ultimately eventual extinction.Relaxation training is also provided, with breathing and imagery exercises being utilised, with the assumption that fear and relaxation cannot coexist, known as reciprocal inhibition.