Productivity & time laws · law 090
Premack Principle
Also known as: Grandma's rule
By Shivam Bhandari · Reviewed 31 October 2026 · How we write
what it means
A preferred activity can be used to reward a less preferred one — do the hard thing first, then the enjoyable thing.
How Premack Principle works
Activities people enjoy can reinforce activities they don't. Linking them — ‘first this, then that’ — builds habits without needing external rewards.
Managers, parents, and individuals use it to schedule work so that the pleasant parts follow the important but less enjoyable parts.
where it comes from
Psychologist David Premack proposed it in 1959 based on experiments with monkeys and children. It is nicknamed ‘Grandma's rule’: eat your vegetables, then you get dessert.
Premack Principle examples in business
Personal productivity
‘No coffee break until I've called three overdue clients.’
Teams
A team does the weekly report first thing on Friday, then gets an early finish.
Customers
An app unlocks fun features after users complete profile setup.
How to apply it
- 1List tasks you avoid and activities you enjoy.
- 2Pair them: avoided task first, enjoyed activity after.
- 3Keep the pairing consistent so the habit forms.
- 4Use the same structure in customer onboarding.
common misreading
It works best when the reward truly follows the task — skipping the order breaks the habit.
ask yourself
Which daily treat could you make conditional on your hardest task?
Frequently asked questions
What is Premack Principle?
A preferred activity can be used to reward a less preferred one — do the hard thing first, then the enjoyable thing. Activities people enjoy can reinforce activities they don't. Linking them — ‘first this, then that’ — builds habits without needing external rewards.
Who came up with Premack Principle?
Psychologist David Premack proposed it in 1959 based on experiments with monkeys and children. It is nicknamed ‘Grandma's rule’: eat your vegetables, then you get dessert.
How do you apply Premack Principle in business?
1. List tasks you avoid and activities you enjoy. 2. Pair them: avoided task first, enjoyed activity after. 3. Keep the pairing consistent so the habit forms. 4. Use the same structure in customer onboarding.
What is a common misunderstanding of Premack Principle?
It works best when the reward truly follows the task — skipping the order breaks the habit.