Which statement describes a fixed action pattern?

• A. A sequence triggered by a single cue and completed once started.
• B. A flexible behavior that can be easily stopped mid-action.
• C. A learned habit that requires reinforcement to persist.
• D. A behavior that is never modified by training.

Answer: (A)

Fixed action patterns are innate, almost automatic sequences of behavior that are triggered by a specific stimulus. Once the trigger starts the pattern, the rest of the sequence unfolds to completion with little to no deviation or need for further input. The described statement fits this idea perfectly: a sequence that is initiated by a single cue and then runs to completion once it begins.

This contrasts with flexible, stoppable actions, which depend on ongoing assessment or intention and can be halted mid-action. It also differs from learned habits that require reinforcement or practice to persist, which involve changes in behavior based on experience. While some innate patterns can be relatively resistant to training, the defining feature of a fixed action pattern is that a single cue sets off an instinctive sequence that proceeds to completion.