People are "turned on" by different things. For this reason, backup reinforcers must be chosen specifically for the individuals involved in the program. Possibilities include consumable reinforcers (e.g., various foods), activity reinforcers (e.g., hobbies), manipulative reinforcers (e.g., puzzles), possessional reinforcers (e.g., baseball hat), and social reinforcers (e.g., hugs). Most importantly, it is essential to provide a variety from which the person can chose. A stimulus that is paired with many different types of backup reinforcers is called a generalized reinforcer. The reinforcing power of a token is affected by the number of different backup reinforcers that are available for it. As Martin & Pear (1998) note, "if there are many different backup reinforcers available, then at any given time at least one of them will probably be strong enough to maintain tokens at a high reinforcing strength for any individual in the program" (p. 127). TV watching may not be a strong reinforcer for a child returning home from a movie; consequently, the child may be less motivated to earn tokens at that time if TV watching is the only backup reinforcer. However, tokens may continue to be desirable if, in addition to TV watching, backup reinforcers include staying up late, a special snack, and the opportunity to help dad fix the car the next day.
There are various ways of determining reinforcers. The participant might examine a reinforcer survey and check off those items which he or she prefers (e.g., see Martin & Pear, 1998, p. 33-34). Also, the participant could be observed to ascertain what activities he or she frequently engages in. According to the Premack Principle, the opportunity to engage in a high probability behavior (e.g., watching TV) can be used to reinforce a low probability behavior (e.g., setting the table). The most important characteristic of a backup reinforcer is that it is indeed a reinforcer, specifically, a stimulus or event that increases a behavior when presented as a consequence of that behavior. A person choosing an item from a reinforcer survey or reporting that they enjoy a certain activity does not guarantee the reinforcing effectiveness of that event. This can only be truly determined by conducting an experimental test.
If access to a backup reinforcer is limited, then that backup reinforcer is likely to be more effective. For example, an allowance may be a stronger backup reinforcer for Joe's behavior if he has no other access to money. One should always keep in mind, however, that individuals in a treatment program cannot be deprived of those things that they have a right to access.
"Such basic rights as nutritious meals, a comfortable physical environment, freedom from harm, reasonable leisure activities, training activities, and reasonable freedom of movement cannot be taken away from an individual and used in a token economy. The reinforcers used in a token economy must be those that are above and beyond the individual's needs and rights" (Miltenberger, 1997, pp. 444-445).