How we change what others think, feel, believe and do
A reinforcer is the stimulus that causes reinforcement. These can be positive or negative, depending on whether they cause positive reinforcement or negative reinforcement. A desired reward is a positive reinforcer.
There are a number of terms related to reinforcement, including:
When a dog sits on command, its owner gives it a biscuit. Next time, the dog is more likely to sit when told. (Positive reinforcement)
A person who is upset has a drink to blunt the emotional pain. They then keep drinking. (Negative reinforcement)
In essence, any stimulus that changes the likelihood of future action is a reinforcer. As we respond to many stimuli, even at an unconscious level, it could be said that all stimuli are reinforcers. This is particularly true in human interaction, where we seek acceptance of others and will note reactions to what we do and then change how we behave in order to gain greater approval.
While stimuli act as reinforcers, reinforcers can also act as stimuli. You can use biscuits as reinforcers to make a dog more likely to sit. Later, if you show the dog a biscuit and it may sit, in hope of receiving the biscuit. Now the biscuit is itself a stimulus.
Cues are not really reinforcers. They are typically commands that have been paired with reinforcing stimuli so they can be used as substitutes. Hence the cue of a raised finger causes a dog to sit, while the reinforcing stimuli is the thought of food or praise that may follow.
Reinforcement can act on memory, for example where a person under repeated interrogation has a false memory implanted.
Reinforcement in its normal usage is 'opposite' to punishment. Punishment includes removing rewards and presenting aversive stimuli. Reinforcement includes giving rewards (positive) and removing aversive stimuli (negative).