At some point in our lives, we have probably all been told first we have to eat our vegetables, and then we can have our dessert. This FIRST → THEN rule is known in behavioural research as the Premack Principle, otherwise referred to as Grandma’s Law.
Just as children may not want to eat their veggies, but will eat them for a slice of Grandma’s pie: Every day we all have to do things that we may not want to do in order to access something that we do want. 

Examples of Grandma’s Law

FIRST (I have to work) → THEN (I get my paycheck)

FIRST (I have to clean the house) → THEN (I can watch TV)

FIRST (I have to get groceries) → THEN (I can eat dinner)

FIRST (I have to do the dishes) → THEN (I can have my glass of wine)

The trend here is that first we have to put in the work, and then we get a reward. This technique is often used as a behavioural intervention when working with children who have work to complete that they may not otherwise be motivated to do.  This strategy can work very well when implemented correctly.

Grandma’s Law in Action

Choose activities/objects that are motivating

Everyone finds different activities/objects rewarding and it will be important to ensure that you are choosing things that are exciting and rewarding to the individual before using this technique.

The things I find rewarding (coffee and wine anyone??) are not going to be reinforcing for a child, and what is rewarding for one child may not be rewarding for another. That is why it is so important to understand what is rewarding to the individual you are using this strategy with before implementing it!

Use clear language

Once you have chosen the reward it is important to use clear language to explain how it is going to work. For children, this is often done visually.  It can be helpful to create a FIRST/THEN chart where you can either put pictures or words in each column. When implementing this technique at work or school make sure that the individual clearly knows what they need to accomplish before they can move onto the rewarding activity.

Make sure the work matches the reward

It is also important that the work matches the reward.  For example, we cannot expect a child to do 2 hours of homework for 3 minutes on the Ipad.  We also would not expect a student to work in class doing an assignment for hours without a break. In order for Grandma’s Law to be successful the work needs to match the reward!

Examples of an appropriate work/reward balance: 

FIRST (5 Math Problems) → THEN (2 Minutes on Ipad)

FIRST (Eat 5 Pieces of Broccoli) → THEN (You may leave the dinner table)

FIRST (Make your bed) → THEN (You may play outside for 15 minutes)

FIRST (Clean the dishes)  → THEN (You may watch TV for 15 minutes)

FIRST (Meet deadline for project)  → THEN (You may take a day off)

Make it fun

If you find this is a helpful tool for your child you could come up with a list of rewards with your child that they can choose from when they have a difficult task they must complete. You also could create a visual together with your child and make it fun (put a picture of their favourite cartoon on the chart and/or print the chart in their favourite colour…)


Jess VanderWier

Registered Psychotherapist & Mom of 3

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