The concept of reinforcement is one of the most important and utilized principles in applied behavior analysis.  The most basic definition of reinforcement is that a type of behavior (R) is followed by a reinforcement (S^R) there will be an increase in the future frequency of that behavior.  Reinforcement can be categorized as types or classes of reinforcement and they are identified through a process called preference assessment. Reinforcement occurs when a behavior increases because of a consequence of either adding or subtracting something from the environment.

Some important attributes of reinforcement:

• The time between the behavior and the consequence.  Immediacy of reinforcement is critical to create the relationship between the behavior and the consequence.
• The conditions present when the behavior occurs
• The motivation present for the desire of the consequence

If a response does not closely follow a behavior, it is not acting as reinforcement.  If a behavior increases because of a long delayed response, then the behavior has increased behavior of a rule governed  behavior or instructional control.  An example of rule governed behavior is when a child receives a reward for a semester of straight As.  If this increases the child’s studying behavior,  it is not due to reinforcement but the rule governed behavior that “if I study more, I will receive future awards.”  Instead, if a child received immediate social praise by a parent or teacher after a study session and this increased the child’s studying behavior, this would be an example of positive reinforcement at work.

2 Term Contingency

Reinforcement is a function of the relation of a consequence immediately following a behavior, which increases the odds that the behavior will occur again in the future.

3 Term Contingency

When a consequence is paired with a behavior, that relationship in combination with the antecedent stimulus, creates a 3 term contingency.  When there is the antecedent, followed by the behavior, which is followed by the consequence, there is a contingency relationship between these.

A discriminative stimulus (S^D) is an antecedent stimulus (thing that happens before the behavior) that is correlated with the availability of reinforcement for that behavior.  Stimulus delta (S^ delta) is the absence of the stimulus, and this does not produce the reinforcement when the behavior is emitted.  For example, given the S^D, “Cell phone ringing” the behavior of “answering the phone and saying ‘hi'” results in the consequence (reinforcement) of having a conversation.  If the phone does not ring (stimulus delta), if you pick up the phone and say “hi”, you will not receive the reinforcement or consequence of having a conversation.

It’s all about motivation

Motivating operations (MOs) are environmental variables that change the value of a consequence, making it a reinforcer or not.  For example, when you have mowed the lawn on a hot day, a cold glass lemonade is much more motivating and rewarding than it is on a cold, snowy day sitting in your pajamas near a fire.