Updated: Oct 1, 2017
Stimulus control refers to how things (stimuli) in the environment impact the likelihood of a behavior occurring. If a behavior is under stimulus control, then that behavior has a higher likelihood of occurring when the stimulus is present. Additionally, the absence of the stimulus would result in a decrease of that behavior.
How is Stimulus Control Established?
A behavior can become under stimulus control when the behavior has been reinforced in the presence of the stimuli.
I put a dollar in the vending machine (behavior) because the lights on the machine are on (stimulus), indicating that the machine is working. In the past, putting a dollar in the vending machine behavior when the light is on has resulted in me getting a tasty snack (history of reinforcement). Conversely, when the lights are off (absence of stimulus), I won't put a dollar in the vending machine (no behavior), because it would not dispense my snack (no reinforcement).
In this scenario, the behavior of putting a dollar into the machine has come under the stimulus control of the light on the vending machine because, in the past, putting money into a vending machine has been reinforced with a snack. The light itself would be called a discriminative stimulus, which is the term used to describe the actual stimuli that increases the behavior. You can read more about
Some of our other favorite examples around the web:
When we have a powerful thunderstorm in our lightning-prone area of the country, my wife and I unplug our computers. Our behavior is "controlled" by the occurrence of the thunderstorms, which are potentially antecedent to a damaging electrical surge. Even the best surge protectors cannot protect against a nearby lightning strike. By reacting to the antecedent stimuli of thunderclaps, we attempt to avoid the punishing stimulus of ruined computers.