Translated from the Portuguese original. Read the original (Português)
Positive reinforcement happens when something is added right after a behavior and, because of that, the behavior starts happening more often. It is how the brain learns what is “worth” repeating. The detail almost everyone gets wrong: it only counts as reinforcement if the behavior actually increased — otherwise, it was not reinforcement at all.
Positive reinforcement is the presentation of a stimulus right after a behavior, which increases the likelihood that the behavior will happen again in the future. It is one of the basic principles of behavior analysis, described by B. F. Skinner.
Watch out for the two words
The name “positive reinforcement” trips a lot of people up, because it uses two everyday words with a very specific technical meaning. It is worth unpacking each one:
- “Positive” does not mean “good” or “pleasant.” In behavior analysis, positive simply means adding something to the environment — placing a stimulus where it was not before. It is the opposite of “negative,” which would mean removing something.
- “Reinforcement” is defined by its effect. We only call it reinforcement when the behavior increases after the consequence. If the behavior did not increase, then — by definition — that was not reinforcement, no matter how much it looked like a reward.
That is why saying “I praised them to reinforce it” is, technically, a bet: you can only confirm reinforcement happened by observing whether the behavior actually started happening more often. It is also why reinforcers are individual: what works for one person may not work for another.
Types of reinforcer
Not all reinforcers are alike. They are commonly split into two broad groups:
- Primary (unconditioned): have direct biological value, without needing any learning — for example, food and water.
- Conditioned (secondary): gained their value through association over a lifetime, such as praise, tokens, and money.
Besides the type, three factors strongly influence how well a reinforcer works:
- Immediacy: the closer the consequence comes to the behavior, the stronger the effect.
- Contingency: there needs to be a clear “if this, then that” relationship between the behavior and the consequence.
- Quality: reinforcers that are truly relevant to that person, at that moment, have a bigger effect.
Reinforcement in everyday life
The same principle shows up at home, at school, and in therapy. In each tab, notice the antecedent → behavior → reinforcement triad:
At home
Antecedent: dinner is over and there are dishes to clear.
Behavior: the child carries their own plate to the sink.
Reinforcement: a warm thank-you and attention from the parents right afterward. If, over the following days, the child starts clearing their plate more often, then the thank-you worked as positive reinforcement.
At school
Antecedent: the teacher asks the class a question.
Behavior: the student raises their hand and takes part.
Reinforcement: specific praise (“great idea, you explained that really well”). If participation increases in the following classes, the praise acted as a conditioned reinforcer.
In therapy
Antecedent: the therapist gives an instruction agreed on with the person.
Behavior: the person performs the target skill.
Reinforcement: a planned, individualized consequence — it could be praise, a token, or access to a preferred activity — always chosen for the effect it produces on that person's behavior.
Reinforcement is not a bribeIt is the most common confusion. A bribe is usually offered during a problem behavior, in the heat of the moment, to stop the disruption (“stop crying and I'll give you candy”). Positive reinforcement is planned ahead of time and defined by its effect: it strengthens the desired behavior that already occurred, instead of rewarding the problem.
Attention reinforces too — sometimes without meaning toFor many people, adult attention is a powerful reinforcer. That is why it is possible, without realizing it, to strengthen unwanted behaviors: if a child only gets a look and a word when they “act up,” that very behavior may be getting reinforced. Watching what increases helps redirect attention toward what you want to see more of.
Test your understanding
Quick quiz
Three questions to reinforce the concept. You'll see the explanation right away.
Further reading
- Skinner, B. F. Science and Human Behavior. New York: Macmillan, 1953.
- Cooper, J. O., Heron, T. E., & Heward, W. L. Applied Behavior Analysis. 3rd ed.
This entry is educational and does not replace assessment, diagnosis or treatment by a qualified health professional. Every person is unique — for a specific case, seek individual guidance.