Stimulus
A stimulus is any physical event or change in the environment that can affect a person's behavior through the senses, such as a sound, sight, touch or smell.
The environment is everything that surrounds the person and can affect their behavior, and it is described in terms of stimuli (plural of stimulus). A stimulus can be an object, a sound, a light, a spoken instruction, another person's action, a temperature, a taste or even a bodily sensation like hunger pain. What matters is that it is a physical event that can be detected.
Stimuli matter because behavior is understood in relation to them. A stimulus that comes before behavior and affects it is an antecedent (for example, an instruction or a toy on the table). A stimulus change that follows behavior is a consequence (for example, praise, a token, or removal of a difficult task). The same stimulus can function differently for different people or at different times, so its role is defined by its effect on behavior.
Task A.5 asks RBTs to describe both behavior and the environment in observable terms. That means describing stimuli concretely, such as "the teacher said 'Line up'" or "a peer took the tablet", instead of vague phrases like "the classroom was stressful". Objective descriptions of stimuli make ABC data, session notes and reports to the supervisor useful.
Example and non-example
| Example | The sound of a fire drill alarm, a caregiver saying "Time for bath", and a plate of crackers placed on the table are all stimuli. |
|---|---|
| Non-example | The client covering their ears is not a stimulus; it is a response to one. |
Don't confuse it with
| Behavior | A stimulus is an environmental event; behavior is the person's action that the stimulus can affect. |
|---|---|
| Antecedent | Stimulus is the general term; an antecedent is a stimulus or condition that occurs before a behavior. |
Test yourself
-
Question 1Which statement describes the classroom environment in observable terms?
Show answer
A: Three peers played music on a speaker near the client. This reports what was physically present and happening, which anyone in the room could confirm.
- B: "Overstimulating" is a judgment about the client's experience, not a description of the room.
- C: "Chaotic" is a vague label; it does not say what was happening.
- D: This infers the client's feelings instead of describing the setting.
Task A.5 · 40-hour curriculum section C
-
Question 2Which of these is a response by the client rather than a stimulus in the client's environment?
Show answer
B: The client points to a picture of juice. A response is an instance of the client's behavior. The other options are environmental events that the client can detect.
- A: A sound from a device is an environmental event, which is a stimulus.
- C: Another person's speech is a stimulus for the client.
- D: A change in lighting is an environmental event, which is a stimulus.
Task A.5 · 40-hour curriculum section C · 40-hour curriculum section A
-
Question 3In behavior analysis, what is a stimulus?
Show answer
D: An event in the environment that a person can detect. A stimulus is an event or change in the environment, such as a sound, sight or touch, that a person can detect through the senses and that can affect behavior.
- A: A feeling belongs to the person, not to the environment, and is not what "stimulus" means.
- B: An action by the client is a response, not a stimulus.
- C: A written goal describes intended outcomes; it is not a stimulus in this sense.
Task A.5 · 40-hour curriculum section C · 40-hour curriculum section A
Answer every question to see your score.
On the RBT exam
This term belongs to task A.5 Describing behavior in observable, measurable terms in content area A, Data Collection and Graphing, which is 13 of the 75 scored questions.