Penelope's little brother has been scaring her by jumping out from behind the refrigerator door and shouting "boo" every time she tries to get a snack. Now, every time Penelope touches the refrigerator door handle, her heart starts racing. In several sentences, describe one example of classical conditioning you have experienced or witnessed in everyday life (ex. training a pet, food dislikes due to illness, conditioned fears, etc.). Identify the unconditioned stimulus, unconditioned response, neutral/conditioned stimulus, and conditioned response in your example.