Unconditioned Stimulus: Unconditioned stimuli are natural stimuli that automatically trigger specific unconditioned responses without any prior learning or conditioning. In our analogy, the unconditioned stimulus would be the hot sand that automatically triggers the reflexive response of jumping back.
Acquisition: Acquisition refers to the initial stage in classical conditioning when an association between a neutral stimulus and an unconditioned stimulus is being formed. In our analogy, if someone were to repeatedly pair a bell sound with receiving an electric shock, they would be in the acquisition phase of training their body to fear that sound.
Higher-order Conditioning: Higher-order conditioning occurs when a conditioned stimulus becomes associated with another neutral stimulus instead of an unconditioned stimulus. This creates a new conditioned response without directly pairing it with an original unconditioned response. An example could be if someone learned to fear spiders (unconditioned response) but then started fearing spiderwebs (new conditioned response) because they associate them with spiders (original conditioned stimulus).