Answer:
The answer is classical conditioning.
Step-by-step explanation:
This refers to the association of a stimulus (in this case, the rattling sound) with an unconditioned stimulus (a bear attack), provoking a conditioned response (fear).
One of the best illustrators of classical conditioning was Ivan Pavlov. He is famous for an experiment in which he rang a bell before feeding a dog. In time, the dog associated the sound of the bell with food. The dog soon started salivating just by hearing the sound.