CHAPTER 10 – Shaping
Shaping happens naturally – babbling to imitating to talking, for example.
Shaping: used to develop a target behaviour that a person does not currently exhibit.
Uses differential reinforcement and successive approximations.
Differential reinforcement: involves the basic principles of reinforcement and
extinction. One particular behaviour is reinforced and all other behaviours are not
reinforced in a particular situation. As result, the behaviour that is reinforced
increases and the behaviours that are not reinforced decrease through extinction.
Successive approximation: shaping steps.
To begin shaping: identify an existing behaviour that is an approximation of the target
behaviour = starting behaviours or first approximation. You reinforce this behaviour =
person exhibits this behaviour more often.
You then stop reinforcing this behaviour and, as a part of extinction burst, novel
behaviours occur. You pick the behaviour that is the closer approximation to the target
behaviour = person exhibits this behaviour more often and the previous behaviour less
This process of differential reinforcement continues until the person finally exhibits the
Successive Approximations to Lever-pressing
1. The rat moves to the side where the lever is located
2. The rat faces the lever
3. The rat approaches the lever
4. The rat rears up on its hind legs
5. The rat makes a movement towards the lever with a paw
6. The rat touches the lever
7. The rat presses the lever
Applications of Shaping
Shaping can be used for:
1. Generating a novel behaviour
a. Language in young child, lever-pressing in a rat
2. Reinstating a previously exhibited behaviour
a. Learning to walk again with a patient that refused PT
3. Changing some dimension of an existing behaviour Research on Shaping
Shown that shaping