Positive emotion stimuli will serve as positive reinforcers. The Law of Effect introduced the relation between reinforcers and punishers. As with primary reinforcers, an organism can experience satiation and deprivation with secondary reinforcers. Tokens must be used as reinforcers to be effective. Much subsequent research in many labs examined the effects on behaviors of scheduling reinforcers. The reinforcers are symbols or tokens that can be exchanged for other reinforcers. Social skills training teaches clients skills to access reinforcers and lessen life punishment. Some primary reinforcers, such as certain drugs, may mimic the effects of other primary reinforcers. They often choose to be bully assistants or reinforcers. B.F. Skinner was well known for his studies of reinforcers on behavior. Most token economies offer a choice of differing back-up reinforcers that can be virtually anything. Guests can often hear these vocal reinforcers when attending a SeaWorld show. There are a couple different types of positive reinforcers. The first problem is that it does not explain how secondary reinforcers reduce drive. Examples of primary reinforcers include food, water, and sex.