Contiguity refers to the principle that objects or events that are close together in space or time are perceived as related. This concept is often used in psychology and learning theories, where it suggests that when two stimuli occur together, they become associated in the mind. For example, if a person hears a bell ring and then receives food, they may start to associate the sound of the bell with the arrival of food. In the context of classical conditioning, developed by Ivan Pavlov, contiguity plays a crucial role. Pavlov's experiments demonstrated that dogs could learn to associate the sound of a bell with food, leading to salivation even when food was not present. This illustrates how the proximity of events can create strong associations in behavior and learning.