Behaviourism · 1959
The Premack principle
What you do most can become the key to doing what you do least… if you learn to arrange them in the right order.
The Premack principle establishes that a high-probability behaviour can function as a reinforcer of a low-probability behaviour when a contingent relationship is arranged between the two. Premack thereby reformulates the classical notion of the reinforcer, shifting it from specific stimuli towards relative patterns of activity within the organism's repertoire. This approach makes it possible to explain the effectiveness of reinforcement in functional and contextual terms, showing that reinforcing value is not intrinsic to a stimulus but depends on the individual's behavioural hierarchy.
Core ideas
-
Reinforcement is a relation between behaviours, not a property of the stimulus
The Premack principle redefines the concept of the reinforcer by showing that one behaviour can reinforce another according to its relative probability of occurrence. Reinforcing value resides neither in the stimulus nor in the activity itself, but in the functional relation between two behaviours within a concrete repertoire. Reference: Premack (1959), *Toward Empirical Behavior Laws*.
-
High-probability behaviours reinforce low-probability ones
A behaviour that occurs with high frequency under baseline conditions can function as an effective reinforcer of a less frequent one when a suitable contingency is established. This principle makes it possible to predict which activities will reinforce which, without recourse to universal or arbitrary reinforcers. Reference: Premack (1959), *Toward Empirical Behavior Laws*.
-
Reinforcing value depends on the individual's behavioural hierarchy
Each organism has its own hierarchy of behaviours ordered by probability of occurrence, and this hierarchy determines which activities can function as reinforcers. The Premack principle thus explains inter-individual variability in reinforcement without appealing to internal motivational differences. Reference: Premack (1965), *Reinforcement Theory*.
-
Reinforcement is dynamic and context-dependent
A behaviour's position in the hierarchy may change according to context, the availability of alternatives and the recent history of activity. The same behaviour may therefore reinforce at one moment and cease to do so at another, showing that reinforcement is neither fixed nor stable. Reference: Premack (1965), *Reinforcement Theory*.
-
Restriction is key to a behaviour functioning as a reinforcer
For a high-probability behaviour to maintain its reinforcing effectiveness, access to it must be restricted outside the contingency. Without restriction, the behaviour–behaviour relation loses force, which shows that reinforcement depends on conditions of access and not only on preference. Reference: Premack (1965), *Reinforcement Theory*.
-
The Premack principle calls the notion of a universal reinforcer into question
By showing that any behaviour can be reinforcing depending on its relative probability, Premack calls into question the idea of universally reinforcing stimuli. Reinforcement ceases to be a fixed list of objects or events and becomes a contextualised functional relation. Reference: Premack (1965), *Reinforcement Theory*.
-
Behaviour–behaviour contingencies can reorganise the repertoire
The repeated application of contingencies based on the Premack principle not only uses the existing behavioural hierarchy but can modify it, increasing the probability of behaviours that were initially infrequent. This shows that the principle has structural effects on the organism's repertoire. Reference: Premack (1965), *Reinforcement Theory*.
Influences
- Operant conditioning
- Psychology of reinforcement
- Objectivist empiricism / Logical positivism
Key references
- Premack, D. (1959). Toward empirical behavior laws: I. Positive reinforcement.
- Premack, D. (1965). Reinforcement Theory.