Which of the following is a characteristic that behavior must have as part of its definition?

Movement is a fundamental characteristic of behavior. Behavior is essentially defined as any observable and measurable action or response exhibited by an organism. This includes physical actions such as walking, speaking, or any form of movement. Behavior can also involve non-movement aspects like thoughts or feelings, but these too must result in some form of observable behavior to be considered within the framework of behavior analysis.

For a behavior to be appropriately defined, it must be something that can be seen, measured, or recorded, which inherently requires a level of movement, whether that is literal physical movement or a change in state or condition due to an interaction. Hence, when identifying behavior, focusing on observable actions that involve movement is crucial to ensuring clarity and consistency in behavior analysis.