Probably one of the most widely known concepts in psychology is the concept of classical conditioning. First demonstrated by Ivan Pavlov, classical conditioning, also called Pavlovian conditioning, shows how certain stimuli (noted as neutral stimuli) can be associated with an original stimulus (noted as the unconditioned stimulus) in order trigger the same response. In his experiment, Pavlov used meat powder (an unconditioned stimulus), which stimulated the dog's salivation (an unconditioned response), and a metronome (a neutral stimulus) which didn't produce salivation. Pavlov then began to associate the two stimuli together, in which the metronome and the meat powder were offered simultaneously in order to encourage the dog's salivation. After allowing the dogs to become use to this routine, Pavlov removed the meat power and learned that the sound of the metronome still produced salivation (a conditioned response here).
Another example of classical conditioning can be found in this entertaining segment:
Although, this observation was useful, anybody can use classical conditioning in their everyday lives. For example, my neighbors, who are dog breeders and trainers, trained their dogs to respond to the different tones of a piano. From kenneling up, to feeding time, to going outside, each one was well orchestrated.
Lilienfeld, Scott. "Stress, Coping, and Health." Psychology: From Inquiry to Understand. Boston: Allyn & Bacon, 2011. 454-87. Print.