Target Terms: Stimulus, Stimulus Class
Definition: Events in the environment that affect the behavior of an individual.
Example in everyday context: You are normally very talkative during work gatherings. When your boss is present, you are less talkative during work gatherings. Your boss serves as a stimulus that changes your behavior.
Example in clinical context: A client with a history of trauma sees a therapist’s shirt that reminds them of their abuser’s shirt, and begins to cry. The shirt (stimulus) had an impact on behavior based on individual learning history.
Example in supervision/consultation context: A supervisor is present during a classroom observation. The teacher becomes very enthusiastic in their tone of voice and engages the students more than usual. The presence of the supervisor is a stimulus and signals the availability of punishment in the event of a poor performance.
Why it matters: All living things react to events in their environment.
Definition: A group of stimuli that are similar along one or more dimensions (for example, they look or sound similar, they have a common effect on behavior, or they occur at similar times relative to the response).
Example in everyday context: You pick up your phone when you hear it ringing, even if your child changed your ring tone to a really weird song. The ring tones coming from your phone act as a group of stimuli that all have the same impact on behavior (you pick up the phone).
Example in clinical context: You are teaching a student how to identify groups of objects. You show a student a banana, kiwi, strawberry and plum. You ask the student, “What are these?” The student says, “Fruit”, even though they are all different fruits.
Example in supervision/consultation context: You teach a staff member to provide help for a client when the client signs for help, says “Help,” or exchanges a picture symbol for help. You are establishing a stimulus class for the staff person. The different stimuli (modes of communication) produce a common behavioral result (provide help).
Why it matters: It is very important for all of us to engage in behavior under the control of a variety of related stimuli in our daily lives. (For example, we need to pull over for emergency vehicles, even though they do not all look and sound exactly the same.) It is also helpful to understand how stimulus classes can contribute to socially significant clinical problems, so that we can then solve them more effectively. (For example, a client may call all animals “Woof woof,” or may act afraid whenever they hear a loud noise because it sounds like a gunshot to them.)