Understanding Reinforcement

An important principle in the practice of Applied Behavior Analysis is the use of reinforcement to strengthen desired behaviors.

The definition of reinforcement is found on its effect on a behavior, not in its form or appearance. In other words, a stimulus that increases the probability that behavior will occur again in the future is deemed a reinforcing stimulus. There are two types of reinforcement, positive and negative.

Positive  Reinforcement

The easiest way to distinguish whether a reinforcer  is positive or negative is by asking yourself “Is this stimulus being added following the desired behavior?”  For example, if a mother praises her child for cleaning his room the praise is the added stimulus that followed the behavior of cleaning the room. So the behavior of cleaning his room is reinforced by the mother’s praise.

Example: A child earns $5 for every good grade in school.

Example: A child earns tokens for every correct answer and then trades in those tokens for a toy or activity of choice.

Negative Reinforcement

In contrast, a reinforcing stimulus is considered negative when you ask “Is a stimulus being removed following the desired behavior?” An example would be a husband doing the dishes to terminate/avoid his wife nagging him about the dishes. So the behavior of doing the dishes is reinforced by the removal of the active or risk of nagging by the wife.

Example: A child eats 2 bites of vegetables so they can get up from the table .

Example: A child washes their hands to get the dirt (determined to be aversive) off their hands.

Example: A child sees non-preferred food on plate and screams, the non-preferred food is taken away.

Consider this last example, see anything familiar? Negative reinforcement is often a driving force behind the shaping and maintenance of maladaptive behaviors.


1) Determining whether a stimulus, either added or removed, is truly functioning as a reinforcer is not always easy. The principles of Applied Behavior Analysis dictate the need for observation, data collection and analysis to determine the function of a potential reinforcing stimulus.

2) People often confuse negative reinforcement with punishment. This is incorrect. Punishment is a behavior reduction procedures, whereas  both positive and negative reinforcement increase the likelihood of that behavior occurring again in the future. Both types of reinforcement can be used as effective procedures for increasing desired behavior.


Stimulus Added

Stimulus Removed

Increases Behavior

Positive Reinforcement

Negative Reinforcement