In classical (or respondent) conditioning, behavior is understood as responses triggered by certain environmental or physical stimuli. They can be "unconditioned", such as in-born reflexes, or learned through the pairing of an unconditioned stimulus with a different stimulus, which then becomes a conditioned stimulus. In relation to motivation, classical conditioning might be seen as one explanation as to why an individual performs certain responses and behaviors in certain situations. For instance, a dentist might wonder why a patient does not seem motivated to show up for an appointment, with the explanation being that the patient has associated the dentist (conditioned stimulus) with the pain (unconditioned stimulus) that elicits a fear response (conditioned response), leading to the patient being reluctant to visit the dentist.