Final answer:
Systematic Desensitization is the technique that uses a hierarchy of fearful experiences to help reduce anxiety, involving a gradual exposure to fears coupled with relaxation techniques or cognitive restructuring.
Step-by-step explanation:
The anxiety reduction technique that involves creating a hierarchy of the client's fearful experiences is known as Systematic Desensitization. This therapeutic method is structured to help clients cope with fears by gradually exposing them to the fear-inducing stimuli or situations, starting with the least frightening and progressively moving to the most terrifying, according to a predefined hierarchy of fear. This process often includes relaxation techniques or cognitive restructuring to facilitate this exposure without the client experiencing overwhelming anxiety.