Premack Principle
The principle that access to a high-probability behaviour can reinforce the performance of a low-probability behaviour.
The Premack Principle (often referred to colloquially as 'Grandma's Rule') states that a learner will complete a non-preferred, low-probability task if it is immediately followed by the opportunity to engage in a highly preferred, high-probability activity. For example: 'Eat your vegetables (low-probability), then you can play outside (high-probability)'.
This principle provides the scientific foundation for First-Then boards and visual schedules. It is a highly effective way to structure demands in a way that uses natural, motivation-based reinforcement contingencies without resorting to arbitrary rewards.
Frequently Asked Questions
What is the Premack principle?
The Premack principle states that a more-preferred (high-probability) activity can reinforce a less-preferred (low-probability) one. Colloquially it is 'Grandma's rule': eat your vegetables, then you can play.
Can you give a Premack principle example?
'Finish your maths, then you can have free time.' The preferred activity (free time) reinforces completing the non-preferred one (maths). It is the basis for First/Then boards.
What is the Premack principle in psychology?
It is a reinforcement principle: giving access to a behaviour the learner does often, contingent on a behaviour they do rarely, increases the rarer behaviour — using natural motivation rather than arbitrary rewards.