Avoidance refers to a behaviorBehavior refers to any activity or action that living organ... that prevents or postpones the presentation of an aversive stimulusStimulus is defined as any change in the environment or for.... In avoidance, the individual engages in a behavior to avoid something unpleasant or undesirable before it occurs, thus reinforcing the behavior because the unpleasant event is prevented.
Example:
A student who dislikes public speaking might pretend to be sick to avoid giving a class presentation. The act of faking illness is reinforced because it successfully avoids the aversive event (the presentation).