When reinforcement occurs after an average number of responses but unpredictably, the schedule is called variable-ratio . It is familiar in gambling devices and systems which arrange occasional but unpredictable payoffs. The required number of responses can easily be stretched, and in a gambling enterprise such as a casino the average ratio must be such that the gambler loses in the long run if the casino is to make a profit. Reinforcers may be positive or negative. Negative reinforcement is not punishment.
Punishment is used to suppress behavior.
It consists of removing a positive reinforcer or presenting a negative one. It often seems to operate by conditioning negative reinforcers. The punished person henceforth acts in ways which reduce the threat of punishment and which are incompatible with, and hence take the place of, the behavior punished. This human species is distinguished by the fact that its vocal responses can be easily conditioned as operants. There are many kinds of verbal operants because the behavior must be reinforced only through the mediation of other people, and they do many different things.