Intermittent Reinforcement
In behaviorism, Intermittent Reinforcement is a conditioning schedule in which a reward or punishment (reinforcement) is not administered every time the desired response is performed. This differs from continuous reinforcement which is when the organism receives the reinforcement every time the desired response is performed. For example, on a continuous reinforcement schedule a mouse who pulls a lever would receive food (reinforcement) every single time it pulled the lever. On an intermittent reinforcement schedule the mouse would only receive food every few times (it is typically random and unpredictable). There is an increased likelihood the desired behavior will continue with intermittent reinforcement conditioning and the behavior lasts longer than continuous reinforcement. Gambling is an example of intermittent reinforcement. You don't win every time or win the same amount when using a slot machine- this wouldn't be exciting or fun. The reinforcement is intermittent and causes a positive and euphoric response in the brain that in some circumstances can lead to gambling addiction.