The Premack Principle

Premack Principle: If behavior B is of higher probability than behavior A, then behavior A can be made more probable by making behavior B contingent upon it.  (Also known as “relativity theory of reinforcement”, based on the work of David Premack)

The Premack Principle is an ABA strategy that is more commonly referred to as “Grandma’s Rule”. The name comes from when Grandmothers (those experts of children’s behavior) say to their grandchildren “You need to eat all your vegetables if you want some chocolate cake”. The child sees the yummy cake, and gulps down the peas in order to access the cake. What Grandma is actually doing has a behavior analytic name, and that name is “Premack Principle”.

Some professionals will also refer to this technique as “First/Then”, “If/Then”, or “High Probability/Low Probability”. Anyone can implement the Premack Principle to gain compliance, or to increase the likelihood of a particular behavior occurring. The Premack Prinicple can be used when you want the child to do something, and they find the behavior to be undesirable. Such as eating their peas, cleaning their room, drinking their milk, putting on a coat before going outside to play, etc. To put it simply: Premack Principle makes it easier to do an unpleasant activity by putting a pleasant activity right after it. 

When using the Premack Principle, you want to explain what the reinforcement is first. So if behavior B is eating chocolate cake and behavior A is eating peas, you would say “If you want a piece of cake, you need to eat all your peas”. Notice the word "if". Another thing I love about the Premack Principle is that accessing the reward is contingent upon completing the task. So if the child still refuses to eat the peas, what happens? They dont get any cake. Its that simple. The child is given the power to earn, or lose the reinforcer.

 A question I get asked sometimes is “Why does it matter which one I say first?” The reason you want to state the high probability behavior first is to prime the child to focus on what they are getting, and not what they are giving/what they have to do. Keep the child’s focus on the reward. If you state what they must do first, all the child hears is the demand. By stating the reinforcing item or activity first, it is often much easier to get a child to comply. 

Some children can handle it if you state the demand first, and for other children you must state the reward first. Typically, when I have clients who have a history of noncompliance then I am careful to state the reward first.

Many parents or professionals get in the habit of giving demands, the child balks or resists, and then the parent or professional reminds the child what they will lose. This is a common error many people make. It usually escalates into a debate or argument that looks something like this:

Parent: “Shawn, go clean your room”

Shawn: “No/I don’t want to/ I’ll do it later”

Parent: “If you don’t clean your room right now then NO video games tonight”

What is the child focusing on right now? They are focusing on the undesirable activity (cleaning their room), and what they will lose (video games). After this exchange, the child typically becomes more and more noncompliant and possibly aggressive, as the parent becomes more and more upset and frustrated.

It’s important to understand the Premack Principle in order to avoid setting yourself up for failure when you present a demand. A quick tip is if you find the words “If” or “First” coming out of your mouth as you are giving a demand, stop and think:

 “Have I clearly presented the reinforcement available?” 

If you have not, then what is the child working for? What does the child earn for compliance?

Don’t focus on or state what the child will lose, no one likes doing things to avoid contacting something negative. We all like doing things to contact something positive. As much as possible, ensure success by being aware of how you present demands. Don’t create situations where it will be likely that the child will refuse to comply. Every demand that comes out of your mouth has the potential of being followed, or being ignored. As the adults, if we are more careful of how we present demands then we can help the child be successful and contact reinforcement much more readily.

Here are a few examples of the correct way to use the Premack Principle (Remember, if the child is very noncompliant its better to state the reward first):

• “We can read a story if you take a bath first.”
• “You can take a 10 minute break if you finish 5 math problems by yourself".
• “First you take a nap, then we’re going to the park!”
• “You can watch 2 DVD’s tonight if you eat all your lunch at school today.”
• “Who wants ice cream? (child raises hand) Okay, hurry and wash the dishes so we can have ice cream!”