What is added to the environment in reinforcement?

In the context of reinforcement, positive reinforcement involves adding a desirable stimulus to the environment following a behavior, which increases the likelihood of that behavior being repeated in the future. This addition of a pleasant or rewarding stimulus can take many forms, such as praise, a reward, or other forms of positive feedback that reinforce the behavior.

Positive reinforcement is fundamentally different from negative reinforcement, which involves the removal of an aversive stimulus, also leading to an increase in the desired behavior but through a different mechanism. Neutral stimuli do not influence behavior in the same way, as they do not enhance or discourage it. Extrinsic factors pertain to influences that come from outside an individual, but the essence of reinforcement specifically concerns the addition of a stimulus that has a direct positive impact on behavior, making positive reinforcement the key concept here.