Premack Principle

The Premack principle is a strategy where access to a high-probability activity is contingent on the occurrence of a low-probability activity. Given two activities with differing probabilities of occurrence during free operant conditions, the occurrence of a lower probability activity can be increased when access to the higher probability activity is made contingent on the occurrence of the lower probability activity. For example, a parent might create a contingency where eating a low-preference food (e.g., brussels sprouts) results in access to a higher preference food (e.g., french fries). At school, a teacher might request that the completion of a low-probability activity (e.g., math worksheet) occur before the student has permission to engage in a high-probability activity (e.g., use of math software on the computer). Functionally, the higher probability activity serves as a positive reinforcer for engaging in the lower probability activity.

The Premack principle can be applied in a variety of settings (e.g., school, home, community) and conditions (e.g., academic, social, vocational) and with diverse populations (e.g., young children, adolescents, adults, talented and gifted, special education, delinquent, general education). As long as the relative reinforcement value of one activity is greater than the reinforcement value of another activity, access to a wide range of activity reinforcers may be used (e.g., tangibles, activities, social).

To enhance the effects of the Premack principle, the following guidelines should be considered: (a) make access to a high-probability activity contingent on (related to) the occurrence of a low-probability activity; (b) specify and teach the contingency rule (“if A, then B”); (c) ensure that the reinforcement value of the contingent activity is greater than the target activity; (d) begin with frequent and immediate access to high-probability activity, then fade to a more intermittent and delayed schedule of access; (e) shift from teacher or other–directed to selfor studentmanaged; (f) to the greatest extent, ensure that highprobability activity is accessible and available on a frequent and immediate basis; and (g) select [Page 1445]high-probability activities that are naturally occurring and appropriate to the context.