ABA glossary
Reinforcement
Definition
A process in which a consequence that follows a behavior makes that behavior more likely in similar situations later. It is defined by its effect on future behavior, not by how pleasant the consequence seems.
In plain words
Reinforcement is what keeps operant behavior going. When a behavior is followed by a consequence and then occurs more often (or longer, faster, or more intensely) under similar conditions, reinforcement has occurred, and the consequence is called a reinforcer. Two words describe every type: positive means a stimulus was added (or increased), negative means one was removed (or reduced), and both strengthen behavior. Because reinforcement is defined by its effect, you only know a consequence is a reinforcer after the behavior increases. Praise, a snack, or a break can work for one learner and do nothing for another, and even a reprimand reinforces behavior if the behavior goes up after it.
Example from a session
During table work, Maya gets 30 seconds with a light-up toy each time she imitates a clap. Over three sessions her correct imitations rise from 4 to 15 per session. The toy is functioning as a reinforcer. On the RBT's data sheet, the evidence is the increase in correct responses, not the fact that Maya smiles at the toy.
For BCBA candidates and supervisors
Analysts separate the operation (delivering a consequence contingent on a response) from the process (the resulting increase in future responding). How well reinforcement works depends on immediacy, contingency, the current motivating operation, magnitude, and the schedule. An item picked in a preference assessment is only a potential reinforcer until a reinforcer assessment or the intervention data show an effect. When reinforcement "stops working," check satiation, delays, and competing contingencies before deciding the item has lost its value. Problem behavior is maintained by reinforcement too, which is why function-based treatment starts by identifying it.
Often confused with punishment, positive reinforcement
Reinforcement always increases future behavior and punishment always decreases it; the words positive and negative do not change that. If behavior goes up after a consequence, it is reinforcement, even when the consequence looks unpleasant. People also use "reinforcement" as shorthand for positive reinforcement, but the umbrella term covers negative reinforcement as well.
Exam tip
Decide the direction first: did the behavior increase in the future? If yes, it is reinforcement. Only then ask whether something was added (positive) or removed (negative). A stem that calls a consequence a "reward" but never shows an increase has not shown reinforcement.
Can you spot reinforcement in a scenario?
Practice BCBA B.4 with exam-style questions and instant feedback.