Which term defines designated responses as members of the targeted response class solely by their common effect on the environment?

• A. Topography
• B. Sequential Response
• C. Functional Definition of Behavior
• D. Stimulus Control

Answer: (C)

The idea being tested is defining behavior by its function—the functional definition of behavior. This means classifying designated responses as part of the same response class based on the environmental effect they produce, not on how they look or how they’re performed. If different movements or actions yield the same consequence, they’re grouped together because their function in the environment is the same.

For example, if both grabbing a toy and asking for it result in obtaining the toy, those distinct forms share the same function (obtaining the toy) and belong to the same functional class. This focus on the environmental outcome rather than the physical form is what the functional definition of behavior emphasizes.

Topography would categorize behavior by its physical form or appearance, which isn’t what this item is asking about. Stimulus control is about how antecedent cues influence whether a behavior occurs, not about grouping responses by the consequences they produce. Sequential response relates to the order or chaining of responses, rather than defining a class by environmental impact.